Reported side effects
The reported side effects of every compound we cover, in one honest place. Where real adverse-effect data exists, it's listed with its severity; where a compound's safety profile hasn't been catalogued yet, we say so plainly rather than inventing risks. Nothing here is a personalized medical judgment — it's information.
As of July 15, 2026 · 164 compounds ·99 with a safety profile documented
- 164compounds tracked
- 99with a safety profile
- 65with itemised effects
Type
Detail
164 compounds shown
| Compound | Reported side effects | Safety note | Evidence context |
|---|---|---|---|
| 5-HTPAmino acid | Summarised in the safety note → | 5-HTP is generally well tolerated on its own, with nausea the main complaint. The real caution is serotonin syndrome — a dangerous build-up of serotonin — if it's combined with SSRIs, SNRIs, MAOIs, triptans or other serotonergic drugs. Do not stack 5-HTP with an antidepressant without medical supervision. | Human (controlled)Mixed |
| ACE-031Peptide |
| Human trials identified nosebleeds, gum bleeding, and telangiectasias, meaning small dilated vessels visible near the skin. The Duchenne trial stopped on preliminary safety data, and no long-term human safety program established a dose that preserves muscle effects without the vascular liability. Products sold online add a separate identity, purity, and sterility risk. | Human RCTHarmful |
| Acetyl Tetrapeptide-3Peptide | Summarised in the safety note → | No long-term human safety trial has isolated acetyl tetrapeptide-3. An FDA laboratory report found reduced viability in cultured dermal papilla cells and keratinocytes after prolonged exposure to higher tested concentrations, but cell toxicity does not establish harm from a finished scalp product. Irritation may also come from solvents, fragrance, preservatives, or other actives in the formula. | In-vitroUnclear⚠ none in humans |
| Acetyl Tetrapeptide-5Peptide | Summarised in the safety note → | Acetyl tetrapeptide-5 has been used topically in small cosmetic tests, but there is no robust independent long-term human safety trial for the ingredient alone. Finished eye products contain other ingredients that can irritate sensitive skin, so a tolerable formula cannot establish the peptide's safety by itself. | AnecdotalUnclear |
| AdipotidePeptide |
| Adipotide has no published human safety results. In monkeys, the principal toxicity was dose-dependent injury and altered function in the kidney's proximal tubules, including elevated creatinine and degenerative or necrotic tubular lesions. Most changes improved during recovery, but the human dose at which kidney injury begins is unknown. | Animal-onlyMixed⚠ none in humans |
| AICARPeptide | Summarised in the safety note → | AICAR has been administered intravenously to people in monitored clinical research, but that does not establish the safety of self-directed use for endurance, fat loss, or longevity. There is no approved label, no validated performance dose, and no long-term safety record for that use. Research-market products add separate uncertainty about identity, purity, and sterility. | Animal-onlyHelped⚠ none in humans |
| AlanineAmino acid | Summarised in the safety note → | Alanine is very safe as part of a normal diet, in which it's one of the most common amino acids. It's not typically taken as an isolated high-dose supplement. | MechanisticUnclear |
| AmycretinPeptide |
| Amycretin has randomized human safety data, but the published trials were early, small, single-center studies sponsored by Novo Nordisk. Gastrointestinal events, especially nausea, vomiting, and diarrhea, were frequent and increased with dose. Most reported events were mild or moderate, but withdrawals were numerous in the subcutaneous study. Long-term safety is not established. | Human RCTHelped |
| AnamorelinPeptide |
| Anamorelin has substantial short-term human trial data in people with advanced cancer, but the safety picture is not trivial. Hyperglycaemia, peripheral oedema, and electrocardiogram conduction changes have been reported. Japan's review also identified important cautions involving liver impairment and CYP3A4 drug interactions. The EMA separately found that trial-site recording problems prevented a thorough evaluation of potential risks in the European application. | Human RCTMixed |
| AOD-9604Peptide | Summarised in the safety note → | AOD-9604 has an unusually good human safety record for a research peptide: it was well tolerated in clinical obesity trials, with no significant effect on blood sugar or IGF-1. That said, long-term human data are thin, and the products sold today are unregulated research chemicals whose purity and dose accuracy vary from vendor to vendor. | Human (controlled)Mixed |
| ARA-290Peptide | Summarised in the safety note → | ARA-290's human safety record comes from small, short Phase 1–2 trials, where it was generally described as well tolerated — reassuring for a research peptide, but a long way from the long-term safety data a real medicine carries. Because it is engineered NOT to raise red blood cells, it lacks EPO's classic clotting/blood-thickening risk, but that is an absence of one known concern, not a clean bill of health. The most concrete real-world risk sits with the unregulated research-chemical supply rather than the molecule itself. | Human RCTMixed |
| ArgirelinePeptide |
| Topical argireline (acetyl hexapeptide-8) is generally well tolerated in cosmetic use. The most commonly reported issues are mild, transient skin irritation or redness at the application site. Because it is applied to the skin rather than injected, systemic exposure is expected to be low, and no serious safety signals have emerged from the small human cosmetic studies. Long-term safety data are still limited. | Human RCTMixed |
| AsparagineAmino acid | Summarised in the safety note → | Asparagine is safe as part of a normal, protein-containing diet, where it's common and constantly produced by the body. It isn't sold as a standalone high-dose supplement. | MechanisticUnclear |
| Aspartic acidAmino acid | Summarised in the safety note → | L-aspartic acid is safe as part of a normal diet, where it's abundant and continuously synthesized. The D-aspartic acid sold as a testosterone booster is a distinct isomer with underwhelming human evidence, not the dietary L form. | Human (controlled)No effect |
| B7-33Peptide | Summarised in the safety note → | B7-33 has no published human safety trial, so its side effects, contraindications, interactions, pharmacokinetics, and long-term risks in people are unknown. A mouse prostate-tumor experiment did not show the growth signal seen with native H2 relaxin, but that narrow result is not a general toxicology program or proof of human safety. Research-market product identity, purity, and sterility add separate risks. | Animal-onlyHelped⚠ none in humans |
| BCAAsAmino acid | Summarised in the safety note → | BCAAs have a strong safety record — anyone eating a protein-rich diet already consumes grams daily, and supplement doses are well tolerated. The sensible cautions are balance (isolated BCAAs can displace the other essential amino acids) and the rare inherited disorder maple syrup urine disease, where BCAAs must be tightly restricted under medical supervision. | Human (controlled)Mixed |
| Beta-alanineAmino acid | Summarised in the safety note → | Beta-alanine is considered safe. The famous tingling (paresthesia) is harmless and dose-related — spreading intake into smaller servings, or using sustained-release forms, minimizes it. No serious adverse effects have emerged from the weeks-long loading protocols used in research. | Human RCTHelped |
| Betaine (TMG)Amino acid | Summarised in the safety note → | Betaine has a strong safety record — it's used as a prescription drug at gram-scale doses. Side effects are usually limited to mild stomach upset or, rarely, a fishy odour at high doses. The one thing to watch is a possible rise in cholesterol with large amounts, so people managing lipids should keep that in mind. | Human RCTHelped |
| BimagrumabPeptide |
| Bimagrumab has been tested in randomized human trials, but it does not have the long-term safety record of an approved obesity medicine. Muscle spasms, diarrhea and acne were common bimagrumab-associated adverse events in BELIEVE. Adverse-event discontinuations were higher with bimagrumab alone than with placebo, semaglutide alone or the combinations, and longer Phase 3 safety data do not yet exist. | Human RCTHelped |
| Biotinoyl Tripeptide-1Peptide | Summarised in the safety note → | No long-term human safety trial has isolated biotinoyl tripeptide-1. A human study of a multi-ingredient topical formula reported generally good tolerability with some mild scalp complaints, but those findings cannot identify the peptide as either the cause or the safe component. Finished-product preservatives, solvents, and other actives matter to topical risk. | In-vitroUnclear⚠ none in humans |
| BPC-157Peptide | Summarised in the safety note → | Human safety data remain limited. A 2025 pilot reported no measured adverse effects after intravenous BPC-157 in two adults, but two previously exposed participants followed for days cannot establish a safe dose or long-term safety. Most safety information still comes from animal studies. | Animal-onlyUnclear |
| BPC-157 + KPV (Gut Stack)Stack | Summarised in the safety note → | Both are research chemicals without long-term human safety data, and the combination has none. People with active GI disease should be especially cautious about self-treating with unregulated compounds instead of established medical care. Oral and injectable forms are both marketed; the animal gut work used varied routes. | AnecdotalUnclear⚠ none in humans |
| CagrilintidePeptide |
| Cagrilintide's side-effect profile in trials looks a lot like the GLP-1 drugs it's often paired with: mostly gastrointestinal — nausea, vomiting, diarrhea, constipation — plus injection-site reactions, usually mild to moderate and worst while the dose is being increased. Because it is still investigational, long-term human safety data are limited, and the research-market powder sold online is unregulated for purity and sterility. | Human RCTHelped |
| CagriSemaPeptide |
| Unlike most research peptides on this site, CagriSema has substantial human safety data — thousands of participants across the REDEFINE Phase 3 program. The side-effect profile is dominated by gastrointestinal effects (nausea, vomiting, diarrhea, constipation) typical of the GLP-1 and amylin classes, mostly during dose escalation. Long-term (multi-year) safety and the cardiovascular-outcomes trial are still reading out. | Human RCTHelped |
| CarnosineAmino acid | Summarised in the safety note → | Carnosine has a clean safety record at supplement doses, with a harmless histidine-related tingling the most common effect at higher intakes. It's not associated with serious adverse effects, though as with any supplement, sensible dosing and a check with a clinician for existing conditions is wise. | Human (controlled)Mixed |
| CartalaxPeptide | Summarised in the safety note → | Cartalax has no established human adverse-event rate, safe dose, pharmacokinetic profile, interaction data, reproductive-safety record, or long-term safety trial. Cell-culture findings cannot establish human tolerability. Conflicting sequence claims in the research market add a separate product-identity risk. | In-vitroUnclear⚠ none in humans |
| CerebrolysinPeptide |
| Cerebrolysin is generally well tolerated in trials, with the common complaints being injection-site reactions, dizziness, headache and a warm or flushed feeling — usually mild and often tied to fast infusion. Serious reactions are rare but reported, and long-term safety data for the off-label "nootropic" use in healthy people essentially doesn't exist. | Human RCTMixed |
| Citrulline MalateAmino acid | Summarised in the safety note → | Citrulline malate has a good short-term tolerability record in the exercise trials that have tested it, typically at 6–8 grams, with mild GI upset the main reported downside. Because the citrulline half raises nitric oxide, anyone on blood-pressure or erectile-dysfunction medication that works through the same pathway should check with a doctor, since the effects can stack. Long-term safety data specifically for the malate pairing is limited. | Human (controlled)Mixed |
| CJC-1295Peptide |
| CJC-1295's clearest published human safety data come from short studies in healthy adults, where injection-site reactions were common. FDA's later compounding review also identified increased heart rate and systemic vasodilatory reactions among serious adverse-event signals, plus an unresolved immunogenicity risk. There is no long-term human safety data. Raising growth hormone and IGF-1 may also bring water retention, joint aches, tingling in the hands and higher blood sugar, while the research-chemical supply chain adds purity, sterility and dose uncertainty. | Human RCTHelped |
| CJC-1295 + IpamorelinStack | Summarised in the safety note → | The individual peptides have early human pharmacokinetic data, but the combination as run in the community has no controlled human outcome trials. Both are research chemicals with vendor variation. Raising GH/IGF-1 is not consequence-free — water retention, joint discomfort and effects on insulin sensitivity are the commonly discussed considerations. | AnecdotalUnclear⚠ none in humans |
| ColostrininPeptide |
| Small human studies generally described Colostrinin as well tolerated. The early Alzheimer's trial reported mild, temporary anxiety, stimulation, insomnia, and tiredness; a 2023 trial reported no adverse effects. Those studies are not large enough or long enough to map uncommon reactions, interactions, or long-term safety, and supplement quality can vary. | Human RCTMixed |
| CortagenPeptide | Summarised in the safety note → | No controlled trial has established an administered human dose, adverse-event rate, contraindications, or long-term safety for Cortagen. Cell and animal experiments cannot answer those questions, and research-market products add separate uncertainty about identity, purity, and sterility. | Animal-onlyUnclear⚠ none in humans |
| CortexinPeptide | Summarised in the safety note → | Cortexin lacks a strong, independently replicated human safety record for healthy nootropic use. Injection adds risks involving sterility, product identity, local injury, and hypersensitivity. Because the active material comes from cattle brain, transmissible-spongiform-encephalopathy controls and source traceability matter; public evidence does not quantify Cortexin's residual prion risk. | Animal-onlyUnclear⚠ none in humans |
| CreatineAmino acid | Summarised in the safety note → | Creatine monohydrate has an exceptional safety record across decades of research at 3–5 grams a day. Expect a small, harmless bump in water weight early on. The old worry about kidney damage applies to people with pre-existing kidney disease, not healthy users; if in doubt, check with a doctor first. | Human RCTHelped |
| DanuglipronPeptide |
| Danuglipron produced the expected GLP-1 gastrointestinal adverse events, with high discontinuation rates in the obesity trial. Pfizer reported that liver enzyme elevations across more than 1,400 participants were in line with approved drugs in the class, but one asymptomatic potential drug-induced liver injury resolved after stopping treatment and led Pfizer to end development. | Human RCTMixed |
| DavunetidePeptide |
| Davunetide was generally well tolerated in the 52-week PSP trial, but intranasal treatment caused more nasal congestion, discomfort, runny nose, and nosebleeds. Serious adverse events were equally numerous in the treatment and placebo groups. That trial does not establish long-term safety in healthy people using an unapproved product for cognitive enhancement. | Human RCTNo effect |
| Decapeptide-12Peptide | Summarised in the safety note → | Topical decapeptide-12 caused no visible irritation or allergy in the five-person controlled pilot, and small open-label reports described generally good tolerability. The database is too small to estimate uncommon reactions or long-term risk. Multi-product studies also make it difficult to assign irritation or tolerability to the peptide alone. | Human (controlled)Helped |
| DefensinsPeptide | Summarised in the safety note → | Inside your body, defensins are normal and essential — the safety question is about giving them, or products sold as them, from outside, and there is essentially no human safety data for that. Defensins can damage host cells at high concentrations in the lab, and any "defensin" sold on the research-chemical market is unregulated for purity, identity and sterility. | MechanisticUnclear⚠ none in humans |
| DihexaPeptide | Summarised in the safety note → | Dihexa has no human safety data at all — no published toxicology in people and no long-term human record. The main theoretical worry is the flip side of its mechanism: it amplifies HGF/c-Met signaling, and an over-active c-Met pathway is linked to several cancers, so the growth-promoting action that might help neurons is also a reason for caution. Real-world risk skews to sourcing — it is sold only as an unregulated research chemical, so purity, dose accuracy and sterility vary. | Animal-onlyUnclear⚠ none in humans |
| DSIPPeptide | Summarised in the safety note → | DSIP has been given intravenously in small, short human studies, but those experiments cannot establish uncommon or long-term harms. FDA's 2026 review found no safety information for the proposed subcutaneous route and identified possible immunogenicity, aggregation, peptide-impurity, and product characterization risks. | Human (controlled)Mixed |
| DulaglutidePeptide |
| Dulaglutide is one of the best-studied peptides on this site, with years of human trial and real-world safety data behind it. The common problems are gastrointestinal — nausea, diarrhea, vomiting. The label also carries a boxed warning about thyroid C-cell tumors (seen in rodents; human relevance unknown) and warnings for pancreatitis, gallbladder disease, and low blood sugar when combined with insulin or a sulfonylurea. | Human RCTHelped |
| EcnoglutidePeptide |
| Human randomized trials consistently report gastrointestinal effects, especially nausea and diarrhea, along with decreased appetite. Events were usually mild to moderate and most frequent during dose escalation, but long-term cardiovascular, renal, and rare-event safety is less established than it is for older GLP-1 drugs. Unapproved online vials add separate identity, strength, purity, and sterility risks. | Human RCTHelped |
| Epidermal growth factor (EGF)Peptide |
| Small topical studies report generally good short-term tolerability, with brief redness or prickling when micro-spicules disrupt the barrier. Long-term cosmetic safety has not been established. EGF deliberately activates a cell-growth pathway, which creates a theoretical tumor-promotion concern, but the available topical trials do not show that EGF serum causes cancer. | Human (controlled)Mixed |
| EpitalonPeptide | Summarised in the safety note → | Epitalon's honest safety answer is "we don't really know in humans." No human safety trial of the synthetic peptide has been published, and long-term human data does not exist. Animal studies reported few obvious toxic effects at the small doses used, which is reassuring but not the same as human safety. The bigger real-world risk is the product itself — research-chemical vials vary in purity and sterility. | Animal-onlyUnclear⚠ none in humans |
| ExenatidePeptide |
| Exenatide has been used by millions of people and studied in hundreds of human trials, so its safety profile is well characterized — a rarity among peptides. Nausea is the most common effect. Serious but uncommon risks include pancreatitis and, with the extended-release form, a rodent-based thyroid C-cell tumor warning. Hypoglycemia is mainly a concern when combined with a sulfonylurea or insulin. | Human RCTHelped |
| FollistatinPeptide | Summarised in the safety note → | Human safety data for the injectable follistatin peptide are essentially absent. What little human safety information exists comes from small gene-therapy trials, where the localized approach was generally tolerated over the study window — which is not the same as establishing that an injected follistatin peptide is safe. Follistatin sits in pathways that also touch reproduction, inflammation and cell growth, so blocking them broadly is not consequence-free, and no long-term human data exist. | Animal-onlyHelped⚠ none in humans |
| FOXO4-DRIPeptide | Summarised in the safety note → | Human safety data for FOXO4-DRI do not exist — it has never been through a clinical trial. Even the animal safety picture is thin: the peptide works by pushing cells to self-destruct through the p53 pathway, and deliberately clearing cells throughout the body is a powerful, still-unstudied intervention in humans. Treat every safety claim about FOXO4-DRI as unproven. | Animal-onlyUnclear⚠ none in humans |
| GABAAmino acid | Summarised in the safety note → | GABA is regarded as very safe at supplement doses, with only mild, transient effects such as tingling or a slight blood-pressure dip at higher intakes. If you take blood-pressure or sedative medication, it's sensible to check with a clinician first, since effects could add up. | Human (controlled)Mixed |
| GDF-11Peptide | Summarised in the safety note → | There is no human safety data for GDF-11 used as a therapy. In animals the picture is actively concerning as well as promising: some studies report high or sustained exogenous GDF-11 inhibited muscle regeneration and drove muscle wasting rather than rejuvenation. Because GDF-11 is a powerful developmental signaling protein, "more" is not obviously "younger" — the dose and context appear to flip the effect. | Animal-onlyMixed⚠ none in humans |
| GHK-CuPeptide |
| GHK-Cu has a long track record as a topical cosmetic ingredient with few reported problems beyond occasional irritation. Injected or systemic use is far less studied in humans. FDA flags compounded injectable GHK-Cu for potential immunogenicity from aggregation and peptide-related impurities and says human safety data are limited. There is no long-term human safety dataset for injected GHK-Cu. | Human observationalMixed |
| GHRP-2Peptide |
| Human safety data come mostly from short-term diagnostic and pharmacology studies, where single or brief GHRP-2 dosing was generally well tolerated. The common acute effects are a transient rise in prolactin and cortisol, a surge in hunger, mild water retention and occasional flushing or tingling. There is no long-term human safety data for the repeated, self-administered use lifters favour — and research-chemical vials are unregulated, so purity and dose accuracy vary. | Human RCTHelped |
| GHRP-6Peptide |
| GHRP-6's core acute effects in humans are well characterized: a GH pulse, a strong appetite surge, and transient bumps in cortisol and prolactin. What is missing is long-term human safety data at the doses people actually use, and the real-world product is an unregulated research chemical, so purity and dose accuracy vary vendor to vendor. Nothing here establishes it is safe to use routinely. | Human RCTHelped |
| GlutathioneAmino acid | Summarised in the safety note → | Oral glutathione and its precursors are generally well tolerated, with mild digestive upset the main complaint. Intravenous glutathione is a separate and more concerning story, linked to serious adverse reactions and used largely for cosmetic skin lightening that regulators have warned about. | Human (controlled)Mixed |
| GlycineAmino acid | Summarised in the safety note → | Glycine is regarded as very safe. It has been used in gram-scale doses in human trials with only mild, transient side effects such as soft stools or nausea at high intakes. | Human (controlled)Mixed |
| GonadorelinPeptide |
| Pulsatile gonadorelin has substantial human clinical experience in reproductive endocrinology, but safety data for intermittent compounded injections used with TRT are sparse. Reported events in pump-treated men include gynecomastia, injection-site induration, and allergic reactions. Product sterility and potency add separate risks when no marketed FDA-approved human product exists. | Human (controlled)Helped |
| Hexapeptide-11Peptide | Summarised in the safety note → | Published safety evidence is thin. A 2015 paper found no significant toxicity in the fibroblast models it tested, but cell viability is not a human irritation, allergy, or long-term safety study. The same paper reported increased matrix metalloproteinase activity and slower fibroblast migration, findings whose practical meaning for normal topical use remains unknown. | In-vitroUnclear⚠ none in humans |
| HexarelinPeptide |
| Hexarelin has more human data than most research peptides, because it was studied in the 1990s as a growth-hormone probe. Acute doses were generally well tolerated, but hexarelin also nudges up prolactin, ACTH and cortisol, and its growth-hormone effect desensitizes with daily use. There is no long-term human safety data for the physique or anti-aging use people actually buy it for, and the product itself is an unregulated research chemical. | Human RCTHelped |
| HGH Fragment 176-191Peptide | Summarised in the safety note → | Direct human safety data on the raw HGH fragment 176-191 are essentially absent. Its stabilized analog AOD-9604 was well tolerated in human obesity trials without disturbing blood sugar or IGF-1, but that is a different, modified molecule — not proof the research-chemical fragment is safe. The biggest real-world risk is the source: research-chemical fragment answers to no regulator, so its purity, the real dose in the vial, and its sterility are never guaranteed. | Animal-onlyUnclear⚠ none in humans |
| HomocysteineAmino acid | Summarised in the safety note → | Homocysteine isn't a supplement you take, so "safety" is really about what a high level signals and what's done about it. A high reading is best treated as a prompt to check B-vitamin status and overall cardiovascular risk, not a number to chase for its own sake. The B-vitamins used to lower it are safe at sensible doses, though very high long-term B6 can cause nerve problems. A markedly high level deserves a proper medical work-up. | Human RCTNo effect |
| HumaninPeptide | Summarised in the safety note → | Humanin has no human safety data for administration, because it has never been given to people in a study. Cell and animal work has not flagged obvious toxicity — reassuring, but not the same as human safety, and there is no long-term human data at all. The most concrete real-world risk is the source: humanin trades only as an unregulated research chemical, so its purity, real dose, and sterility carry no guarantee. | Animal-onlyUnclear⚠ none in humans |
| HydroxyprolineAmino acid | Summarised in the safety note → | Hydroxyproline is safe at the levels supplied by food and by collagen or gelatin supplements, and it carries no notable toxicity there. It isn't commonly sold or used as an isolated high-dose supplement, so most people simply get it from collagen-rich foods and from their own body's handiwork. | MechanisticUnclear |
| IGF-1 DESPeptide |
| Nobody has established the safety of IGF-1 DES in humans. Animal studies show that poorly binding IGF-1 variants can lower blood glucose and increase organ weights, while the approved native IGF-1 drug carries serious hypoglycemia and neoplasia warnings. Those findings identify credible risks; they do not provide an adverse-event rate for IGF-1 DES. Research vials add identity, purity, dose, and sterility uncertainty. | Animal-onlyUnclear⚠ none in humans |
| IGF-1 LR3Peptide |
| No human safety data exists for IGF-1 LR3 — every risk here is read off IGF-1 biology and animal work, not measured in people using it to build muscle. Hypoglycemia is the most predictable: IGF-1 lowers blood sugar (it's the headline warning on mecasermin, the approved native-IGF-1 drug), which is why cautious users keep fast-acting carbs on hand. Animal data adds organ and tissue overgrowth — infused Long R3 IGF-1 enlarged guinea-pig organs — and IGF-1's pro-growth, anti-cell-death signaling raises a real, unsettled cancer-promotion concern. And because most of what's sold is reagent-grade cell-culture material rather than a pharmaceutical, a vial's true identity and dose ride on a seller who never had to prove either. | Animal-onlyUnclear⚠ none in humans |
| IpamorelinPeptide |
| Human safety data come mostly from small, short pharmacology studies, where ipamorelin was generally well tolerated — the most common effects were a brief head-rush or warmth, headache, mild water retention and tingling. There is no long-term human safety data, and the main open question is what repeatedly raising growth hormone and IGF-1 does over months and years. | MechanisticUnclear⚠ none in humans |
| Kisspeptin-10Peptide | Summarised in the safety note → | Acute intravenous KP-10 studies have not raised major safety concerns, but they were small and short. Long-term treatment safety, repeated subcutaneous or intramuscular use, and clinically useful dosing are not established. FDA also identified unresolved immunogenicity, aggregation, impurity, and formulation risks for compounded injections. | Human (controlled)Helped |
| KlothoPeptide | Summarised in the safety note → | No completed human trial has established the safety of raising alpha-klotho through plasmid or mRNA delivery, and no long-term safety data exist for healthy people. The registered studies are designed to collect tolerability and laboratory safety data, so adverse-event frequencies are not yet known. | Human observationalUnclear |
| KPVPeptide | Summarised in the safety note → | No one has been safely studied on KPV. FDA's 2026 review found no human exposure data by any route (oral, topical, or injected) and none of the standard toxicity studies — acute, repeat-dose, genotoxicity, reproductive, or carcinogenicity — for KPV free base or KPV acetate. "Only three amino acids" describes its size, not a safety record, and no reported problems is not the same as proven safe. The complaints that circulate are mild and purely anecdotal: injection-site reactions, brief flushing, and skin irritation from topical use. A wrinkle specific to KPV: FDA flagged inconsistent naming and impurity controls across its salts, so a vial labeled only "KPV" may not pin down which chemical form is inside. | Animal-onlyHelped⚠ none in humans |
| L-ArginineAmino acid | Summarised in the safety note → | Arginine is well tolerated for most people, with digestive upset the main complaint at higher doses. Caution is warranted for anyone recovering from a heart attack, or taking blood-pressure or erectile-dysfunction medication, since arginine acts on the same nitric-oxide pathway. | Human (controlled)Mixed |
| L-Carnitine / ALCARAmino acid | Summarised in the safety note → | L-carnitine is generally safe at typical supplement doses; high intakes can cause nausea, cramping or a fishy body odor. The unsettled link between carnitine, the gut byproduct TMAO, and heart risk is worth discussing with a doctor if you have cardiovascular concerns before taking it regularly. | Human (controlled)Mixed |
| L-CitrullineAmino acid | Summarised in the safety note → | L-citrulline has a good tolerability record in human trials at several grams a day, and it's gentler on the stomach than high-dose arginine. People on blood-pressure or erectile-dysfunction medication that also affects nitric oxide should check with a doctor, since the effects can stack. | Human (controlled)Mixed |
| L-CysteineAmino acid | Summarised in the safety note → | Cysteine from food is safe and part of every normal diet. Supplemental forms are generally well tolerated; high doses can cause gastrointestinal upset, and NAC in particular should be used thoughtfully alongside medications. | Human (controlled)Mixed |
| L-DOPAAmino acid | Summarised in the safety note → | As a prescription medicine, levodopa has a long, well-mapped safety record. Short-term the main issues are nausea (blunted by carbidopa), lightheadedness on standing and sometimes vivid dreams; long-term use brings dyskinesias, motor fluctuations, and occasional impulse-control problems common to dopamine drugs. The Mucuna supplement route carries the same dopamine effects plus one extra hazard: the L-DOPA dose per capsule is often unknown, so it can't be dosed reliably and can clash with real Parkinson's medication. Involve a doctor before combining it with levodopa or an MAO inhibitor. | Human RCTHelped |
| L-Glutamic acidAmino acid | Summarised in the safety note → | Glutamic acid is safe as a normal part of the diet and is one of the most abundant amino acids in food. Dietary MSG is well tolerated in controlled testing for the general population. | Human (controlled)No effect |
| L-GlutamineAmino acid | Summarised in the safety note → | Glutamine is well tolerated and one of the more benign supplemental amino acids in healthy people. Those with liver or kidney disease should seek medical advice first, since glutamine participates in the body's nitrogen and ammonia handling. | Human (controlled)Mixed |
| L-HistidineAmino acid | Summarised in the safety note → | Histidine is safe as part of a normal diet and has been used in trials without reported problems. High-dose supplementation is less well characterised, and because it is the precursor to histamine, large amounts warrant caution. | Human observationalMixed |
| L-IsoleucineAmino acid | Summarised in the safety note → | Isoleucine is safe at the levels found in food and in balanced BCAA supplements, and it's part of everyone's normal protein intake. The main caution is balance with the other branched-chain amino acids. People with maple syrup urine disease or related BCAA-metabolism disorders must restrict it under medical care. | Human (controlled)Mixed |
| L-LeucineAmino acid | Summarised in the safety note → | Leucine has a strong safety record and is consumed in grams every day by anyone eating a protein-rich diet. Supplemental doses used in trials are well tolerated. People with rare inborn errors of BCAA metabolism (such as maple syrup urine disease) are the exception and must restrict it under medical care. | Human (controlled)Helped |
| L-LysineAmino acid | Summarised in the safety note → | Lysine has a good safety record and is eaten in grams daily in protein-rich diets. Supplemental doses are generally well tolerated, with occasional mild digestive upset at high intakes. As always, starting at the lower end is the sensible move. | Human (controlled)Mixed |
| L-MethionineAmino acid | Summarised in the safety note → | Methionine from a normal protein-rich diet is safe and necessary. The caution is with high isolated supplemental doses, which raise homocysteine and aren't advisable without a specific reason and good B-vitamin status. People with rare disorders of methionine or homocysteine metabolism must manage intake medically. | Animal-onlyUnclear |
| L-OrnithineAmino acid | Summarised in the safety note → | L-Ornithine is generally well tolerated, with mild digestive upset the main issue at higher doses. People with serious liver or kidney disease should only use it under medical supervision, since those organs handle its metabolism and ammonia clearance. | Human (controlled)Mixed |
| L-PhenylalanineAmino acid | Summarised in the safety note → | Phenylalanine from a normal protein-rich diet is safe for the general population. The one crucial exception is phenylketonuria (PKU): people with this inherited condition cannot process phenylalanine and must restrict it under medical care, which is why aspartame-containing products carry a phenylalanine warning. | Human (controlled)Mixed |
| L-ProlineAmino acid | Summarised in the safety note → | Proline is safe as part of a normal diet and in the collagen and gelatin foods that provide it. Isolated high-dose supplementation is uncommon and less thoroughly studied, so moderation is reasonable. | MechanisticUnclear |
| L-SerineAmino acid | Summarised in the safety note → | Serine is safe as part of a normal diet, and supplemental L-serine has generally been well tolerated in studies. Very high doses are less well studied, so a conservative approach is sensible. | Human (controlled)Mixed |
| L-TheanineAmino acid | Summarised in the safety note → | L-theanine is regarded as very safe at the 100–400 mg doses used in research, with no serious side effects reported and no jitteriness. A small number of people feel mildly drowsy at higher doses. It's the rare calming agent that doesn't cloud thinking. | Human (controlled)Helped |
| L-ThreonineAmino acid | Summarised in the safety note → | Threonine is well tolerated as part of normal protein intake, and it's a routine ingredient in nutrition products and animal feed. Dietary amounts raise no real safety concern; high isolated supplemental doses have limited human data, so moderation is the sensible default. | Human (controlled)Mixed |
| L-TryptophanAmino acid | Summarised in the safety note → | Tryptophan from a normal diet is very safe. Supplemental doses are generally well tolerated but can cause drowsiness; people on antidepressants or other serotonergic drugs should talk to a clinician first. | Human (controlled)Mixed |
| L-TyrosineAmino acid | Summarised in the safety note → | Tyrosine has a good safety record at supplemental doses, with only mild, occasional side effects. Caution applies for anyone on MAOI medication or with thyroid disease, since tyrosine feeds both catecholamine and thyroid-hormone pathways. | Human (controlled)Helped |
| L-ValineAmino acid | Summarised in the safety note → | Valine is safe at the levels found in food and in balanced BCAA supplements, and it's part of everyone's ordinary protein intake. Balance with the other two branched-chain amino acids is the main consideration. People with maple syrup urine disease or related disorders must restrict it under medical supervision. | Human (controlled)Mixed |
| LactoferrinPeptide |
| Short oral trials suggest lactoferrin is generally well tolerated, but large long-term safety trials are lacking. A 28-day randomized trial in 66 healthy adults found no excess adverse events with recombinant human lactoferrin up to 3.4 g/day, although the study was industry-linked and focused on immunogenicity. Bovine and milk-derived products can pose a serious risk to people with cow's- milk protein allergy, and supplement quality is not equivalent to drug review. | Human RCTMixed |
| LarazotidePeptide |
| In its clinical trials larazotide was generally well tolerated, which fits its design — it acts locally in the gut and is minimally absorbed, so it doesn't circulate through the body the way an injected peptide does. The most commonly reported side effects were headache and gastrointestinal symptoms, at rates often close to placebo. Because no larazotide product was ever approved, there is no long-term, post-market human safety record, and any "larazotide" sold outside a trial is an unregulated research product of unknown purity. | Human RCTMixed |
| LiraglutidePeptide |
| Liraglutide has years of human safety data behind it — unusual for a peptide. The most common issues are gastrointestinal (nausea, vomiting, diarrhea), usually worst during dose escalation and easing over time. Less common but serious concerns include acute pancreatitis and gallbladder disease, and it carries a boxed warning for thyroid C-cell tumors based on rodent studies. It is a prescription medicine, not a research chemical. | Human RCTHelped |
| LivagenPeptide | Summarised in the safety note → | Livagen has no published controlled human safety trial, so adverse-event frequency, contraindications, interactions, pharmacokinetics, and long-term risks are not established. Cell and animal findings cannot answer whether an injected or oral product is safe in people. Research-market products add separate uncertainties around identity, dose accuracy, purity, and sterility. | In-vitroUnclear⚠ none in humans |
| LL-37Peptide | Summarised in the safety note → | Human safety data for supplemental LL-37 are limited to a few small early trials (a topical wound cream, tumor injections). LL-37 is a natural part of human immunity, but "your body makes it" is not the same as "injecting extra is safe": at higher concentrations LL-37 is cytotoxic to host cells (it can rupture red blood cells in the lab) and is implicated in driving inflammation in conditions such as psoriasis and rosacea. There is no long-term human safety data for LL-37 used this way, and the research-chemical supply is unregulated. | Animal-onlyMixed⚠ none in humans |
| MacimorelinPeptide |
| Macimorelin is given once for a supervised diagnostic test, and its short-term adverse-event record is based on human studies. Unpleasant taste, dizziness, headache, fatigue, nausea, and hunger were reported. The main serious warning is QT prolongation, which can trigger a dangerous heart rhythm; interacting drugs can also distort the test result. Long-term carcinogenicity and fertility studies have not been conducted because Macrilen is not labeled for chronic use. | Human RCTHelped |
| MariTidePeptide |
| Gastrointestinal adverse events were common in Phase 2, especially nausea, vomiting, diarrhea, and constipation. Lower starting doses and gradual dose escalation reduced these problems, but the candidate has no approved label and no post-marketing safety record. Phase 3 is testing whether a slower start can keep the weight-loss effect while making treatment easier to tolerate. | Human RCTHelped |
| MatrixylPeptide |
| Matrixyl is one of the better-tolerated cosmetic peptides. Used topically at the low concentrations found in leave-on serums and creams, it rarely causes more than occasional mild irritation, and it has a long track record as an over-the- counter skincare ingredient. It has not been studied for swallowing or injecting, and the "collagen-boosting" claim is stronger in a lab dish than on a face. | Human (controlled)Helped |
| MazdutidePeptide |
| Mazdutide's side effects in trials are dominated by gastrointestinal complaints — nausea, diarrhea, vomiting and reduced appetite — usually mild to moderate, dose-related, and typical of GLP-1-based drugs. Long-term data, and data outside the largely Chinese trial populations, are still accumulating. | Human RCTHelped |
| Melanotan IPeptide |
| Because afamelanotide is FDA-approved, it has real human safety data — the effects reported most in trials were nausea, headache, fatigue and skin darkening, and its label carries a standing recommendation for twice-yearly full-body skin checks because it darkens moles. That data is for the SCENESSE implant; the gray-market injectable "Melanotan 1" powder is unregulated, so purity and dose accuracy vary. | Human RCTHelped |
| Melanotan IIPeptide |
| Melanotan II's tanning effect is real, but so are its downsides. Nausea and facial flushing are common early on, and the effect that matters most is on the skin itself: Melanotan II can darken existing moles and prompt new ones, which makes tracking any change in a mole harder at exactly the wrong time. Case reports link Melanotan II use to melanoma and to changes in atypical moles. Long-term human safety data do not exist, and the vials sold online are unregulated research chemicals of variable purity and sterility. | Human (controlled)Helped |
| MelitanePeptide | Summarised in the safety note → | Melitane's honest safety answer is "not established in published human research." It is used as a low-percentage topical ingredient in cosmetic formulations, and there are no published standalone human safety trials to point to. The likely real-world risks are the ordinary hazards of a finished topical formula, including irritation or allergic contact reactions in sensitive skin. Melitane is not a sunscreen, and stimulating pigment does not make UV exposure safe. | MechanisticUnclear⚠ none in humans |
| MGF peptidePeptide | Summarised in the safety note → | MGF peptide has no established human safety profile, and FDA says it has found no human exposure data for drug products containing PEG-MGF by any route. The agency flags possible immune reactions, peptide-related impurities, and problems characterizing the active ingredient. Long-term risks, pharmacokinetics, and a safe human dose are unknown. | In-vitroMixed⚠ none in humans |
| MK-677Peptide |
| MK-677 has more human safety data than almost any compound sold on the research market, and that data is a mixed bag. It reliably causes water retention, a bump in appetite, and higher blood sugar with lower insulin sensitivity. A trial in frail elderly hip-fracture patients was stopped early after more heart-failure events in the MK-677 group — a warning that matters most for older or cardiovascular-risk users. It is not an approved medicine, and long-term use in healthy adults is unstudied. | Human RCTMixed |
| Modified GRF 1-29Peptide |
| Human safety data on modified GRF 1-29 specifically are thin. Most of what we can say is borrowed from the FDA-approved GHRH analog sermorelin and from general growth-hormone-secretagogue use, where the common complaints are mild and local — injection-site reactions, flushing, occasional headache or water retention. That's reassuring context, not a safety guarantee for this exact research-chemical peptide, and there is no long-term human safety record for it. | MechanisticUnclear⚠ none in humans |
| MOTS-cPeptide | Summarised in the safety note → | Human safety data on injected MOTS-c is essentially nonexistent. MOTS-c is a peptide your own mitochondria already make, but that does not tell us whether dosing extra of it is safe — the safety information that exists comes from short mouse studies, and there is no long-term human data. The most concrete real-world risk is the product itself: it is sold as an unregulated research chemical, so what's actually in a given vial — purity, true dose, sterility — rides on a vendor you're mostly trusting on faith. | Animal-onlyUnclear⚠ none in humans |
| N-Acetyl Semax AmidatePeptide | Summarised in the safety note → | N-Acetyl Semax Amidate has no published human safety trial and no established adverse-event rate, contraindication list, dose, or interaction profile. Parent Semax data cannot close that gap because terminal modification can alter a peptide's chemistry and biological behavior. Research-market identity, purity, aggregation, and nasal-product quality add separate uncertainties. | MechanisticUnclear⚠ none in humans |
| NAC (N-acetylcysteine)Amino acid | Summarised in the safety note → | NAC is well established and generally safe; oral use may cause nausea or a sulfur smell, and it's an actual approved medicine for overdose and mucus. Because it can affect clotting and blood pressure, and interacts with some medications, talk to a doctor before regular high-dose use — especially around surgery. | Human RCTHelped |
| NAD+Peptide |
| NAD+ and its precursors are generally well tolerated in trials, with mild, short-lived effects most common — nausea, flushing and GI upset with oral precursors, and flushing, nausea or chest and abdominal cramping when an IV drip runs too fast. Long-term safety of deliberately pushing NAD+ up for years is not established, and because NAD+ fuels cell growth and repair, there is a theoretical concern about feeding an existing cancer. | Human RCTMixed |
| Nonapeptide-1Peptide | Summarised in the safety note → | Nonapeptide-1 has no published long-term human safety trial as a standalone ingredient. Small randomized studies of multi-ingredient topical products reported adverse events at the finished-product level, which cannot identify the peptide as the cause or rule it out. Irritation or allergy remains possible with any topical formula, and safety depends on the whole product. | In-vitroUnclear⚠ none in humans |
| NoopeptPeptide |
| Noopept was generally well tolerated in the clinical studies that exist, with mild, reversible side effects — but those studies were small, mostly in cognitively-impaired patients, and there is no long-term human safety data and no trial in healthy adults. The most consistently reported issues are irritability, disturbed sleep, headache and, in people with existing hypertension, a rise in blood pressure. | Human (controlled)Helped |
| OrforglipronPeptide |
| Orforglipron cleared FDA review, so unlike most compounds on this site it has a real human safety record. Its side effects are the familiar GLP-1 class pattern — mostly gut-related (nausea, diarrhea, vomiting, constipation), usually mild to moderate and often easing as the body adjusts. Long-term, real-world safety data are still accumulating, as they are for every drug in this young class. | Human RCTHelped |
| OxytocinPeptide |
| Hospital oxytocin has well-characterized, potentially serious obstetric risks and requires monitoring. Excessive uterine stimulation can harm both mother and fetus; prolonged high-dose infusion can cause water intoxication and seizures. The 24-week autism trial found similar adverse-event incidence and severity with intranasal oxytocin and placebo, but that does not establish long-term safety for compounded nasal use or healthy-person social enhancement. | Human RCTMixed |
| P021Peptide | Summarised in the safety note → | P021's honest safety answer is "we don't know in humans." The tolerability data come from rodent studies, where P021 was given by injection and orally without obvious toxic effects — reassuring for a research direction, but not the same as human safety. There is no human safety trial and no long-term human data at all. | Animal-onlyUnclear⚠ none in humans |
| Palmitoyl Tetrapeptide-7Peptide |
| The Cosmetic Ingredient Review Expert Panel concluded that palmitoyl tetrapeptide-7 is safe in cosmetics at the practices and concentrations it reviewed. A human repeated-insult patch test of a trade-name mixture containing 500 ppm was negative for irritation and sensitization, while an in-vitro eye irritation assay classified that mixture as slightly irritating. These findings cover low-concentration topical cosmetic use, not swallowing or injection. | In-vitroUnclear⚠ none in humans |
| Palmitoyl Tripeptide-1Peptide |
| Palmitoyl tripeptide-1 has a long, quiet track record as a leave-on cosmetic ingredient and is generally very well tolerated on the skin. The main reported problem is ordinary formulation stuff — mild irritation, redness or a sensitivity reaction, usually tied to a preservative or the base rather than the peptide. There is no meaningful human safety data for injecting it or using it any way other than topically. | In-vitroUnclear⚠ none in humans |
| Palmitoyl Tripeptide-38Peptide | Summarised in the safety note → | Published human safety evidence for isolated palmitoyl tripeptide-38 is sparse. Topical cosmetic formulas containing it have generally been reported as well tolerated, but those results apply to whole products and short study periods. There is no established safety record for swallowing or injecting it. | In-vitroUnclear⚠ none in humans |
| PancragenPeptide | Summarised in the safety note → | Pancragen does not have a usable human safety record. One brief clinical abstract reports metabolic changes but provides no detailed adverse-event accounting, and no registered clinical trial was found. A compound intended to affect glucose regulation could plausibly cause unwanted glucose changes, but their frequency and severity have not been measured. | Human observationalUnclear |
| PE-22-28Peptide | Summarised in the safety note → | PE-22-28 has no published human safety dataset, established adverse-event rate, or long-term toxicity record. Cell experiments reported selectivity for TREK-1 over several related channels and no hERG effect under the tested conditions, but those assays cannot establish safety in a person. Research-market product identity, purity, and sterility add separate unknowns. | Animal-onlyUnclear⚠ none in humans |
| PemvidutidePeptide |
| Human randomized trials provide a useful short-term safety picture, with gastrointestinal effects such as nausea, vomiting, diarrhea and constipation most prominent. IMPACT reported few discontinuations due to adverse events through 24 weeks, but Phase 2 trials cannot establish the safety of longer or wider use. Pemvidutide remains investigational. | Human RCTMixed |
| Pentadeca ArginatePeptide | Summarised in the safety note → | Pentadeca arginate is one of the newest healing peptides on the market and one of the least studied: zero human trials, no toxicology program, and no published safety data on the arginate salt itself. Because it carries BPC-157's exact peptide chain, it inherits BPC-157's unsettled safety questions rather than answering them — the arginine counter-ion changes the packaging, not the risk picture. What users report is mild and short-lived — brief fatigue after a dose, injection-site redness or bruising, mild digestive changes on the oral form — but none of it is confirmed in controlled data, and there is no long-term human safety record at all. | AnecdotalUnclear⚠ none in humans |
| Pentapeptide-18Peptide | Summarised in the safety note → | Pentapeptide-18 has no published standalone long-term human safety trial. Supplier testing and use inside multi-ingredient serums have not produced a clear safety signal, but they cannot establish adverse-event frequency or systemic exposure. The practical topical risks include irritation or allergy from the finished formulation; the pharmacological significance of any peptide that crosses skin is unknown. | In-vitroUnclear |
| PetrelintidePeptide |
| ZUPREME-1 found similar overall adverse-event and serious-adverse-event rates with pooled petrelintide and placebo, but nausea was more common with petrelintide. Most gastrointestinal events were mild. One 51-week Phase 2 trial cannot establish long-term safety, rare harms, or safety in routine care. | Human RCTHelped |
| PidotimodPeptide |
| Short pediatric trials generally found pidotimod well tolerated, and a 29-trial meta-analysis found no increase in adverse events overall. That is useful human safety evidence, but it does not establish rare-event, long-term, pregnancy, or U.S.-market product safety. | Human RCTMixed |
| PinealonPeptide | Summarised in the safety note → | Pinealon does not have a well-characterized human safety profile. Published cell and animal experiments cannot establish common adverse effects, rare harms, interactions, reproductive safety, or long-term risk in people. Research-use-only products add separate uncertainty about identity, purity, potency, and sterility. | Animal-onlyUnclear⚠ none in humans |
| PramlintidePeptide |
| Symlin carried a boxed warning for severe insulin-induced hypoglycemia, particularly in type 1 diabetes and usually within three hours after injection. Nausea, vomiting, reduced appetite, and headache were common. The label required careful patient selection, frequent glucose monitoring, separate injections from insulin, and a large initial reduction in mealtime insulin under professional supervision. | Human RCTHelped |
| PT-141Peptide |
| PT-141 is better-studied for safety than almost any peptide sold this way — thousands of women took it in the Vyleesi approval trials. Nausea is close to universal on the first dose (about 40% of women) and usually eases with later ones. Every dose briefly raises blood pressure and lowers heart rate, so it isn't for anyone with uncontrolled high blood pressure or known cardiovascular disease. Repeated dosing can darken the skin, face, or gums, and that pigment may not fully fade after stopping. | Human RCTHelped |
| PyrrolysineAmino acid | Summarised in the safety note → | Pyrrolysine isn't taken, eaten, or sold to people, so it has no human safety profile to speak of — there's simply no exposure to assess. It belongs to microbial biochemistry and the protein-engineering bench, and this page covers it for completeness rather than as anything you'd consume. | In-vitroUnclear⚠ none in humans |
| RapastinelPeptide | Summarised in the safety note → | Rapastinel was generally well tolerated in controlled human trials, with a tolerability profile similar to placebo in the three acute Phase 3 studies and no psychotomimetic signal. Development ended after lack of efficacy, so there is no approved label or postmarketing record defining long-term risks. | Human RCTNo effect |
| RetatrutidePeptide |
| Retatrutide has more human safety data than most compounds on this site, because it has reported phase 3 trials — but it is still investigational and its long-term profile is being filled in during ongoing phase 3 studies. The most common side effects are gastrointestinal (nausea, vomiting, diarrhea, constipation), dose-related and usually heaviest early on. Like other incretin drugs, it carries a rodent thyroid C-cell tumor signal whose human relevance is unsettled, and it raises heart rate in a dose-dependent way. | Human RCTHelped |
| SAMeAmino acid | Summarised in the safety note → | SAMe is generally well tolerated, with stomach upset, insomnia or anxiety the main side effects at higher doses. The important cautions are bipolar disorder, where it can trigger mania, and combining it with antidepressants or other serotonergic drugs, which risks serotonin syndrome. Use it under medical guidance if either applies to you. | Human (controlled)Helped |
| SelankPeptide |
| Selank's human safety record comes mainly from its clinical use in Russia as an anxiety drug, where it has been described as well tolerated, non-sedating and free of the dependence that dogs benzodiazepines — a genuine point in its favor. The caveats: the safety data is short-term and mostly from one country, long-term and independent Western data are thin, and US research-chemical vials are unregulated for purity and sterility. | Human RCTHelped |
| SelenocysteineAmino acid | Summarised in the safety note → | Selenocysteine itself is not something you take, so its safety comes down to selenium intake, which has a narrow safe window. Enough selenium is required to build working selenoproteins; too much causes selenosis (garlic breath, hair and nail loss, gastrointestinal upset). Aim to meet, not exceed, selenium needs — more is not better, and overdoing Brazil nuts or high-dose supplements can push you past the safe ceiling. | Human observationalMixed |
| SemaglutidePeptide |
| Semaglutide is one of the most-studied peptides in humans, so its risks are well characterized rather than guessed at. The common side effects are gastrointestinal — nausea, vomiting, diarrhea, constipation — usually worst during dose increases. Less common but serious concerns include pancreatitis and gallbladder disease, and the label carries a boxed warning about thyroid C-cell tumors seen in rodents, which is why it is contraindicated in people with a personal or family history of medullary thyroid cancer or MEN 2. | Human RCTHelped |
| SemaxPeptide | Summarised in the safety note → | Semax is generally reported as well tolerated, and Russia's decades of clinical use as a nasal medicine is reassuring. But rigorous long-term Western safety data is limited, most controlled data comes from short courses, and the research-grade powder sold outside Russia is unregulated — so what a given vial actually contains — purity, true dose, sterility — comes down to the seller. | Animal-onlyUnclear |
| SermorelinPeptide |
| Sermorelin was generally well tolerated across its years as an approved drug. The most common issues are injection-site reactions (redness, swelling, pain), with flushing, headache, and occasional dizziness or nausea also reported. Because sermorelin raises your own GH and IGF-1, it carries the theoretical growth-hormone-axis caution shared by all GH therapies — it is not for use in active cancer or pregnancy — and there is no long-term human safety data for the anti-aging use. | Human (controlled)Mixed |
| Sermorelin + IpamorelinStack | Summarised in the safety note → | Sermorelin has a longer clinical history than most research peptides (it was once an approved diagnostic/therapeutic agent), but the sermorelin + ipamorelin combination as run today has no controlled human outcome data. As with any GH-raising approach, water retention, joint discomfort and insulin-sensitivity effects are the usual considerations. | AnecdotalUnclear⚠ none in humans |
| SetmelanotidePeptide |
| Setmelanotide has real human safety data from its FDA trials. The most common issues are injection-site reactions, skin darkening (including the darkening of existing moles, because it also nudges the pigment receptor MC1R), nausea and headache. Its label carries warnings for spontaneous erections in males, changes in sexual arousal, and depression or suicidal thoughts, and it calls for a full skin exam before and during treatment. | Human RCTHelped |
| SLU-PP-332Peptide | Summarised in the safety note → | SLU-PP-332 has no human safety dataset: no clinical adverse-event rates, safe dose, contraindications, interaction studies, or long-term follow-up. Short mouse experiments cannot settle those questions. Products sold online add separate identity, purity, and dose-accuracy risks because no FDA-approved formulation exists. | Animal-onlyHelped⚠ none in humans |
| SNAP-8Peptide | Summarised in the safety note → | SNAP-8 is a topical cosmetic peptide, and topical peptides at cosmetic concentrations are generally well tolerated, with mild application-site irritation or redness the most commonly discussed complaint. There is no published long-term human safety trial for SNAP-8 specifically, and — as with any skincare active — the real-world risk skews toward the finished product (formulation, preservatives, contaminants) rather than the peptide alone. | MechanisticUnclear⚠ none in humans |
| SomatropinPeptide |
| Somatropin has extensive human safety data in approved populations, but the risk depends on diagnosis, age and dose. Fluid retention, joint or muscle pain, tingling and impaired glucose tolerance are established adverse effects. Serious warnings include intracranial hypertension, pancreatitis, worsening diabetic retinopathy and tumor progression or recurrence in susceptible patients. | Human RCTHelped |
| SS-20Peptide | Summarised in the safety note → | SS-20 has no established human safety profile. Published experiments use cells, isolated organs, mice, or rats and do not answer questions about long-term toxicity, immune reactions, interactions, fertility, pregnancy, or a safe human dose. Research-market product identity and sterility add separate uncertainty. | Animal-onlyHelped⚠ none in humans |
| SS-31 (elamipretide)Peptide |
| Here SS-31 is unusual for a "longevity peptide": because elamipretide went through full clinical trials and FDA review, its short-term human safety is far better characterized than something like BPC-157. The most common problem across trials was injection-site reactions. What still doesn't exist is long-term data in healthy people taking it purely for anti-aging. | Human (controlled)Mixed |
| SurvodutidePeptide |
| Survodutide has real human safety data, which sets it apart from most research peptides. The most common side effects in trials were gastrointestinal — nausea, vomiting, diarrhea and constipation — mostly mild to moderate and tied to how fast the dose was raised. Slow dose titration reduced them. Long-term safety and heart-outcome data are still being gathered in the phase 3 program. | Human RCTHelped |
| Syn-AkePeptide | Summarised in the safety note → | Syn-Ake is used as a topical cosmetic peptide and is generally considered well tolerated at cosmetic concentrations, with local irritation the main reported concern. The honest gap: there is very little peer-reviewed human safety data on Syn-Ake specifically, and no long-term data. As a large, water-soluble peptide it is not expected to be absorbed deeply, but that expectation has not been well characterized in published studies. | MechanisticUnclear⚠ none in humans |
| TaurineAmino acid | Summarised in the safety note → | Taurine has a strong safety record. Doses of one to three grams a day are common in human studies with few side effects, and it doesn't carry the jittery downside of the caffeine it's usually paired with. As always, start low and see how you respond. | Human observationalMixed |
| TB-500Peptide | Summarised in the safety note → | Human safety data for TB-500 are essentially absent. What exists comes from animal work and from anti-doping analytical studies that detect it rather than test its safety. There is no long-term human safety data, and the research- chemical products people actually buy are unregulated for purity and sterility. | Animal-onlyUnclear⚠ none in humans |
| TeduglutidePeptide |
| Teduglutide has substantial human safety data, but its growth-promoting action creates a serious trade-off. The FDA label warns that it may accelerate neoplastic growth and reports intestinal polyps, requiring colonoscopy and upper-GI surveillance. Other important risks include intestinal obstruction, gallbladder or pancreatic disease, fluid overload, and increased absorption of oral medicines. | Human RCTHelped |
| TeriparatidePeptide |
| Teriparatide has substantial human safety data from osteoporosis trials and postmarketing use. Common adverse reactions include joint pain, other pain, and nausea. Important risks include transient high calcium, dizziness or orthostatic hypotension after early doses, kidney-stone concerns, and a rat osteosarcoma signal that has not translated into an increased risk in human observational studies; human data beyond two years remain limited. | Human RCTHelped |
| TesamorelinPeptide |
| Tesamorelin's common complaints are fluid retention, joint and muscle aches, injection-site reactions, and tingling or numbness in the hands — the fluid-driven carpal-tunnel feeling users describe most. By raising growth hormone and IGF-1 it can nudge blood sugar upward, and it is off-limits with active cancer, a pituitary disorder, or in pregnancy. Two safety lanes exist: the prescription Egrifta carries real FDA-trial safety data, while gray-market "research" tesamorelin stacks unverified purity, dose, and sterility on top of that same biology. | Human RCTHelped |
| TesofensinePeptide |
| Tesofensine's main safety problem is cardiovascular: because it raises noradrenaline and dopamine, it tends to push up heart rate and blood pressure, and that — not a lack of effect — is why its obesity development stalled. Human trials also reported dry mouth, insomnia, nausea, constipation and mood or agitation changes. There is no long-term human safety record, and the research-market product is unregulated. | Human RCTHelped |
| The GLOW Peptide StackStack |
| None of the three components has long-term human safety data as injected here, and the three-way combination has none. Product labels and tested vial contents vary. GHK-Cu carries copper; BPC-157 and TB-500 can present immunogenicity and peptide-impurity concerns; and any multi-dose injectable adds sterility, contamination and dosing-error risks. A label from another GLOW product is not a safe substitute for the label in hand. | AnecdotalUnclear⚠ none in humans |
| The KLOW StackStack | Summarised in the safety note → | Four research-chemical peptides with no combined human data and no long-term human safety record for any of them as used here. Every additional compound multiplies the unknowns — and, if combined into one draw, the contamination risk. GHK-Cu's copper content is a specific reason to keep it separate from oxidation-sensitive partners. | AnecdotalUnclear⚠ none in humans |
| The Wolverine StackStack | Summarised in the safety note → | Neither component has long-term human safety data, and the combination has none at all. Both are sold as research chemicals, so purity and dose accuracy vary by vendor. The most-discussed theoretical concern is shared: because both are linked to angiogenesis, people reasonably ask whether they could feed something you wouldn't want to grow — not established in either direction. | AnecdotalUnclear⚠ none in humans |
| ThymalinPeptide | Summarised in the safety note → | Thymalin has an unusually long clinical-use history — decades as a registered immunomodulator in Russia — where it was generally described as well tolerated. That track record is reassuring but not the same as modern long-term safety data, which is thin by Western standards. Because thymalin is extracted from animal thymus tissue rather than chemically synthesized, it also carries the theoretical concerns of any tissue-derived biologic: allergic or immune reactions and contamination if purification is poor. In the US it is sold as an unregulated research chemical, so purity, dose accuracy and sterility vary by vendor. | Human (controlled)Mixed |
| ThymogenPeptide | Summarised in the safety note → | Thymogen has clinical-use history in Russia and some short human studies, but there is no modern, independently replicated long-term safety dataset for healthy immune or anti-aging use. The exact target, human pharmacokinetics, repeat-course risks, interactions, and risks in pregnancy or autoimmune disease remain poorly defined. Products sold through the U.S. research market add separate uncertainty about identity, purity, and sterility. | Animal-onlyUnclear⚠ none in humans |
| ThymopentinPeptide | Summarised in the safety note → | Older controlled trials did not report a clear excess of serious adverse events, but they do not provide a modern, long-term safety record for thymopentin use. Its immune effects make unsupervised use especially uncertain in autoimmune disease, immune suppression, pregnancy, and alongside immune-active medicines. | Human RCTMixed |
| Thymosin Alpha-1Peptide |
| Thymosin alpha-1 has one of the better human safety records among research peptides — it has been given to tens of thousands of patients in registered trials and is a licensed medicine abroad, with mild injection-site reactions the most common complaint. The main caveat is conceptual: it modulates the immune system, so active autoimmune disease and deliberate immunosuppression (such as after an organ transplant) warrant real caution. | Human RCTMixed |
| Thymosin Beta-4Peptide | Summarised in the safety note → | Thymosin beta-4 was generally well tolerated in the small completed human trials (topical eye drops and early systemic studies), with no major safety signal reported — but those trials were small and short, and there is no long-term human safety data for the muscle-recovery use people inject it for. The most-discussed theoretical concern is the flip side of its mechanism: a peptide that drives cell migration and new blood-vessel growth raises the reasonable, unproven question of whether it could feed something you would not want to grow. | Animal-onlyUnclear⚠ none in humans |
| ThymulinPeptide | Summarised in the safety note → | Thymulin is a hormone the body already makes, which is reassuring in principle, but that does not make injecting extra thymulin automatically safe — human safety data are limited and mostly come from older, small clinical studies rather than modern trials, and there is no long-term safety data for the research-market use. The bigger practical risk is the source: thymulin is sold only as an unregulated research chemical, and an unregulated vial's purity, dose, and sterility are only as trustworthy as a seller no one is auditing. | Human observationalMixed |
| TirzepatidePeptide |
| Tirzepatide's most common side effects are gastrointestinal: nausea, diarrhea, vomiting and constipation, heaviest while the dose is being raised and usually settling as the body adjusts. Less common but serious are acute pancreatitis, gallbladder disease, dehydration that can injure the kidneys, and low blood sugar when it is paired with insulin or a sulfonylurea. It carries a boxed warning for thyroid C-cell tumors seen in rats (human relevance unknown) and must not be used by anyone with a personal or family history of medullary thyroid carcinoma or MEN 2. The approved pen is the product the trials measured; self-mixed "research" powder is a separate, untested risk. | Human RCTHelped |
| TrofinetidePeptide |
| Trofinetide has controlled human safety data and longer-term exposure data, but gastrointestinal adverse effects are common. In the pivotal study, diarrhea occurred in 82% of Daybue-treated patients versus 20% on placebo, vomiting occurred in 29% versus 12%, and 12% lost more than 7% of baseline weight versus 4% on placebo. Dehydration, treatment discontinuation, and aspiration after vomiting are practical risks. | Human RCTHelped |
| VesugenPeptide | Summarised in the safety note → | Vesugen has no adequate controlled human safety program and no long-term human trial. Small reports do not establish adverse-event rates, contraindications, interactions, dose accuracy, or product sterility. One human report also noted pro-oxidant activity and a decrease in circulating CD34-positive cells, findings whose clinical meaning remains unclear. | In-vitroUnclear |
| VilonPeptide | Summarised in the safety note → | Vilon has no modern, well-reported human safety program, so its adverse-event rate, interactions, pharmacokinetics and long-term risks are unknown. Cell and mouse tolerability cannot establish human safety. Research-market products add separate uncertainty about identity, purity, dose accuracy and sterility. | Animal-onlyUnclear⚠ none in humans |
| VIPPeptide |
| VIP's main effects double as its side effects: as a potent vasodilator it can drop blood pressure and cause flushing, and because it drives intestinal secretion it can cause diarrhea. Infusing it can trigger headache. Unlike most compounds on this site, VIP has real trial safety data — but there is no long-term safety profile for the intranasal "recovery" use, and research-grade material sold to the public is unregulated for purity and sterility. | Human RCTMixed |
| VK2735Peptide |
| VK2735 has short-term human safety data, not an approved drug label or a long-term safety record. Gastrointestinal events such as nausea, constipation, vomiting, and diarrhea were common in Phase 2. Higher doses caused more treatment stops in the injection study. Gray-market products add separate uncertainty about identity, dose accuracy, storage, purity, and sterility. | Human RCTHelped |
How to read this database
Each row shows the side effects reported for one compound. When a compound has anitemised adverse-effect breakdown, each effect appears as a chip whose colour and label mark its severity. When it has only a prose safety note — the norm for food-derived amino acids with well-characterised tolerability — that note carries the picture instead. The evidence context badge tells you how strong the underlying human data is: an "animal-only" badge means the safety picture rests largely on animal studies, not proof of human safety.
A blank effect list never means "no side effects." For many research peptides the honest answer is that adverse effects have not been systematically itemised in humans yet — so we point to the compound's own safety section rather than implying a clean bill of health the data can't support. As individual compound pages add cited adverse-event data, it flows into this table automatically.