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Things Sold as Peptides That Aren't Peptides
The things sold as peptides that aren’t peptides include MK-677, NAD+, 5-amino-1MQ, tesofensine, orforglipron, and niacinamide. They share storefront categories, not chemistry. MK-677 and orforglipron are small molecules, NAD+ is a nucleotide coenzyme, and niacinamide is vitamin B3. Noopept is the useful exception: a modified dipeptide.
What actually decides whether something is a peptide?
A peptide is decided by structure: amino acids joined through peptide bonds. A compound does not become a peptide because it affects a peptide receptor, raises a peptide hormone, arrives in a vial, or appears under a vendor’s “peptides” tab. The peptide-versus-protein glossary covers the size boundary; this page applies the bond test to the shelf.
That distinction sounds fussy until one product is orally active, another is a vitamin-derived coenzyme, and a third has only been tested for weight loss in mice. Calling all three “peptides” hides differences in absorption, manufacturing, evidence, and regulation. The menu label is doing inventory work, not chemistry.
Which things sold as peptides aren’t actually peptides?
MK-677, NAD+, 5-amino-1MQ, tesofensine, orforglipron, and niacinamide all fail the peptide definition. PubChem shows discrete non-peptide structures for each. Their evidence also lands on different rungs, so “not a peptide” is only the first correction—not a verdict that every compound is useless, unsafe, or equally studied.
| Compound | What PubChem shows | Honest evidence read |
|---|---|---|
| MK-677 (ibutamoren) | Orally active non-peptide small molecule; a ghrelin-receptor agonist and growth-hormone secretagogue | Human randomized trials exist, including a 65-person study in older adults. That makes the evidence human, not the molecule a peptide. |
| NAD+ | Dinucleotide coenzyme: two nucleotide units linked through phosphate groups | Human biology is established. Claims for a particular NAD+ product, route, or longevity outcome still need their own evidence. |
| 5-amino-1MQ | Quinolinium small molecule, not an amino-acid chain | Weight and metabolic findings are preclinical: the foundational 5-amino-1MQ study used cells and diet-induced obese mice, not people. |
| Tesofensine | Small bicyclic organic molecule and triple monoamine reuptake inhibitor | Human randomized evidence exists; a 203-person phase 2 obesity trial tested tesofensine. The drug class is still not peptide. |
| Orforglipron | Non-peptide small molecule that activates the GLP-1 receptor | Human randomized trials supported FDA approval as Foundayo in April 2026. Receptor name and molecule type are separate facts. |
| Niacinamide | Small pyridinecarboxamide, also called nicotinamide | Established as a form of vitamin B3; NIH explains that tissues use niacin to make NAD. No peptide bonds appear along the way. |
| Noopept | N-phenylacetyl-L-prolylglycine ethyl ester | A modified Pro-Gly dipeptide. The structural label is legitimate; efficacy is a different question. |
Is MK-677 a peptide?
No. If you are asking is MK-677 a peptide, the precise answer is that ibutamoren is a non-peptide small-molecule ghrelin-receptor agonist. MK-677 mimics ghrelin signaling and prompts growth-hormone release, which explains why vendors park it beside growth-hormone-releasing peptides. A similar destination does not mean the molecules took the same road.
The classification matters in sport, too. USADA lists ibutamoren and MK-677 as prohibited at all times. That status follows its growth-hormone-secretagogue activity, not peptide chemistry. The full MK-677 reference keeps mechanism, human outcomes, and regulatory facts in separate boxes.
Is NAD or niacinamide a peptide?
No to both. If you are asking is NAD a peptide, NAD+ is a dinucleotide coenzyme used in electron-transfer reactions. If you are asking is niacinamide a peptide, niacinamide is nicotinamide, a form of vitamin B3 and a precursor the body uses to make NAD. Neither molecule is an amino-acid chain.
The NIH niacin fact sheet identifies nicotinamide as niacinamide and explains its conversion to NAD. “NAD peptide therapy” therefore combines a product category with the wrong chemical noun. The NAD+ reference covers the molecule without pretending that established cellular biochemistry proves every infusion or longevity claim.
Is orforglipron a peptide?
No. If you are asking is orforglipron a peptide, orforglipron is a non-peptide small-molecule GLP-1 receptor agonist. GLP-1 itself is a peptide hormone; the receptor keeps that name regardless of what activates it. A key can fit a lock without being made from the same material as the original key.
Orforglipron also shows why current sourcing matters. FDA approved Foundayo on April 1, 2026, and the current DailyMed label identifies it as a prescription tablet. Older pages calling orforglipron investigational are now stale. New approval still does not rewrite the molecule into a peptide.
Is Noopept really a peptide?
Yes, with a qualifier: Noopept is a substituted Pro-Gly dipeptide, chemically modified at both ends. PubChem identifies the prolylglycine structure, and a mechanism paper describes Noopept as a substituted Pro-Gly dipeptide. This is the counterexample that keeps the audit honest instead of turning “vendor says peptide” into an automatic punchline.
Noopept’s name does not end in “-peptide,” while non-peptides sit inside peptide catalogs. Names and shelves are both unreliable classifiers. Check the structure first, then grade the evidence for the specific claim. The site’s evidence-grading guide starts that second job; chemistry cannot finish it for you.
How should you read a vendor’s peptide category?
Treat a vendor’s peptide category as a marketing aisle, not a scientific taxonomy. Ask three separate questions: what is the molecule, what human outcome has actually been tested, and what is its current regulatory status? A clean answer to one does not fill in the other two. Conveniently, neither does a white vial.
For things sold as peptides that aren’t peptides, the honest sequence is structure first, evidence second, status third. PubChem settles the structural question. Human trials or candid “mouse-only” labels settle the evidence tier. FDA, DailyMed, and anti-doping sources settle time-sensitive status. The seller’s navigation menu settles only where the product appears on the screen.