HGH Fragment 176-191

HGH fragment 176-191 is a synthetic copy of the fat-burning tail of human growth hormone, sold as a research chemical for weight loss. In animals HGH fragment 176-191 boosted fat breakdown, but there is no human trial of the raw fragment — the version actually tested in people is its modified cousin, AOD-9604. It is not FDA-approved.

What is HGH Fragment 176-191?

HGH fragment 176-191 is a lab-made peptide — a short chain copied from the tail end (around amino acids 176–191) of human growth hormone, the stretch that carries GH’s fat-burning job. Chemically it is a mid-sized peptide: molecular formula C80H127N23O24S2 and a molecular weight around 1,859 daltons (PubChem CID 172966176). The idea behind HGH fragment 176-191 is simple — keep the part of growth hormone that burns fat and leave the rest behind. It is not a medicine you can be prescribed and not a legal supplement; in the United States HGH fragment 176-191 exists only as a research chemical.

How does HGH Fragment 176-191 work?

HGH fragment 176-191 works by copying only the fat-burning part of growth hormone. Whole growth hormone does several jobs at once — it drives tissue growth, raises IGF-1, and can push blood sugar up — but its fat-burning power lives mostly in that C-terminal tail. Think of growth hormone as a key ring with several keys on it; HGH fragment 176-191 is meant to be just the one key that opens the fat-burning lock, with the growth and blood-sugar keys snapped off. In lab and animal studies HGH fragment 176-191 stimulated lipolysis (the breakdown of stored fat) while apparently sparing the blood-sugar and IGF-1 effects that whole growth hormone has. The honest caveat: exactly how HGH fragment 176-191 behaves in a living human body has not been pinned down.

What does the research show?

HGH fragment 176-191’s evidence is preclinical, and the details matter. In animal models, HGH fragment 176-191 increased fat breakdown and blunted fat gain, and early lab work explored the same lipolytic effect on isolated fat tissue. What is missing is a human trial of the raw fragment itself: a search of PubMed returns only a handful of records, and ClinicalTrials.gov shows no registered study. Here is the part people mix up: the molecule that was actually carried into human obesity trials is AOD-9604 — the 176-191 region with a tyrosine added to make it more stable and drug-like — and even AOD-9604, which was safe in those trials, did not deliver meaningful weight loss over placebo. So for HGH fragment 176-191 specifically, the grade is Animal-only with a None-in-humans flag: the fat-loss story is promising in rodents and unknown in people. That gap isn’t a dead end so much as a line that was never crossed — the human testing went to the cousin, not the original. See how we grade evidence on our evidence-grading page.

What the community reports

Outside the lab, HGH fragment 176-191 has a steady following among lifters and dieters chasing the last bit of stubborn fat, usually late in a cut and often paired with fasted cardio. The commonly reported pattern is a small subcutaneous injection once or twice a day for several weeks. These accounts are anecdotal — they are not controlled data, they lean on people who were already dieting hard, and they carry survivorship bias, since the folks who saw nothing tend to stop posting. HGH fragment 176-191’s community reports are useful for understanding why people try it, not for proving it burns fat.

Is HGH Fragment 176-191 safe? Side effects

HGH fragment 176-191’s honest safety answer is “we barely have human data.” Direct safety studies of the raw fragment in people are essentially absent. Its stabilized analog AOD-9604 was well tolerated in human obesity trials and, unlike whole growth hormone, did not meaningfully raise blood sugar or IGF-1 — a reassuring signal, but AOD-9604 is a different, modified molecule, so that record does not transfer to the research-chemical fragment. The biggest real-world risk with HGH fragment 176-191 isn’t the peptide so much as the vial: sold as a research chemical, it is unregulated, so no one is verifying that the powder is pure, correctly dosed, or sterile before it reaches you. Anyone injecting it also takes on the ordinary risks of self-injection — irritation, bruising, and infection if sterility or technique slips.

FDA & legal status (2026)

HGH fragment 176-191 is not FDA-approved, and it is not a legal dietary supplement either. In the United States HGH fragment 176-191 is sold strictly as a research chemical, with no marketed medicine built on it (FDA). Treat any legal-status claim as dated: enforcement around research peptides is an active area, so re-check before relying on it. The full dated breakdown is in the FDA & legal status block below.

How is HGH Fragment 176-191 used, and can it be mixed?

HGH fragment 176-191 typically comes as a lyophilized (freeze-dried) powder that has to be reconstituted — mixed with bacteriostatic water — before use. Getting the concentration right is pure arithmetic, and our reconstitution & dosing calculator turns “a 5 mg vial, 2 mL water, a 250 mcg target” into the exact number of insulin-syringe units to draw. People also ask whether HGH fragment 176-191 can share a syringe with other fat-loss or growth-hormone peptides; our mixing compatibility reference covers what is commonly combined and where the honest answer is “not enough data.” None of this is a personal protocol — it’s reference math, for information only.

HGH Fragment 176-191 vs AOD-9604

HGH fragment 176-191 and AOD-9604 are close cousins and constantly confused. In short: HGH fragment 176-191 is the raw C-terminal piece of growth hormone, while AOD-9604 is that same region modified — a tyrosine added — to make it more stable and drug-like. Both are pitched for fat loss and both act on the same lipolytic pathway. The key difference is the evidence: AOD-9604 is the one that actually went through human obesity trials (where it was safe but underwhelming on weight loss), while the raw HGH fragment 176-191 has no human trial at all. For the broader picture, see the FDA-approved visceral-fat peptide tesamorelin and the metabolic peptides in the growth-hormone peptides hub, or the newer fat-loss route of a GLP-1-style agonist like retatrutide.

Frequently asked questions

Does HGH fragment 176-191 actually work for fat loss?

Not that anyone has proven in people. HGH fragment 176-191 increased fat breakdown in animals, and the mechanism is real, but there is no human trial of the raw fragment. The closest human data come from its modified cousin AOD-9604, which was safe but did not produce meaningful weight loss over placebo. Treat the fat-loss claim as a hope grounded in animal data, not a tested result.

Is HGH fragment 176-191 the same as AOD-9604?

No — they are close but not identical. HGH fragment 176-191 is the unmodified tail-end of growth hormone; AOD-9604 is that same 176-191 region with a tyrosine added to make it more stable. AOD-9604 is the version that was actually studied in human obesity trials, which is exactly why the two get mixed up.

Is HGH fragment 176-191 legal?

HGH fragment 176-191 is legal to buy and sell as a research chemical in the United States, but it is not an approved drug and not a lawful dietary supplement, and it cannot be sold for human consumption. That is why every vendor labels it “for research use only.”

Is HGH fragment 176-191 banned in sport?

Yes. WADA’s Prohibited List covers growth hormone and its fragments under S2 (peptide hormones and growth factors) and names hGH 176-191 as an example, so HGH fragment 176-191 is prohibited at all times for athletes under anti-doping rules. You can confirm current status through GlobalDRO.

How do people take HGH fragment 176-191?

In the community literature HGH fragment 176-191 is almost always reconstituted with bacteriostatic water and injected subcutaneously, often a few hundred micrograms a day and frequently timed around fasted cardio. That is a reported pattern, not a tested protocol — no human trial has validated any dose of the raw fragment.

Who is HGH Fragment 176-191 for — and who should be cautious?

HGH fragment 176-191 tends to draw in people deep into a cut who want to nudge one stubborn area and like the idea of a fat-loss signal that doesn’t touch blood sugar or IGF-1 the way growth hormone does. The honest framing: the mechanism is well mapped and the animal signal points the right way, but the raw fragment has no human trial behind it, the reassuring safety record belongs to its modified cousin AOD-9604, and the product you’d actually buy is an unregulated research chemical. Anyone expecting a proven fat-loss drug, or unwilling to accept that the human efficacy question is still open, has good reason to keep expectations low and treat HGH fragment 176-191 as an experiment rather than a settled tool.