HGH Fragment 176-191

What it is

HGH Fragment 176-191 is the last 16 amino acids of growth hormone, snipped off so you get the fat-mobilizing signal without the blood sugar, water and IGF-1 effects of the whole hormone. It is a cutting-cycle add-on with a mild effect, not a fat-loss drug, and the price of a 12-week run buys a lot of semaglutide.

The people who use it: already-lean lifters on a cut who want a little extra fat mobilization around fasted cardio, and people who are nervous about full growth hormone and want a version with none of its side effects. It is not for someone with 40 pounds to lose; a GLP-1 does that job and this does not. The idea is clean on paper. GH burns fat through its tail end and raises blood sugar and IGF-1 through other parts of the molecule, so a fragment of the tail should burn fat and do nothing else. In animals that selectivity mostly held up.

What you notice: not much, honestly, and that is the realistic expectation. People who respond describe slightly easier fat loss in the stubborn spots over 8 to 12 weeks, on a diet and training plan that would have worked anyway. There is no appetite effect, no energy effect and no muscle effect; if you feel a buzz, it is the fasted cardio. If you are not in a calorie deficit it does nothing visible at all. Give it eight weeks on a real cut before you judge it, and judge it against what the cut alone was doing. The run matches the cut and stops when the cut ends; there is no known tolerance, so there is no fixed cycle to follow.

How people run it: 250 to 500 mcg subQ, fasted, first thing in the morning or before fasted cardio, with 300 mcg the most common dose. The timing is the whole protocol: it mobilizes fat only when insulin is low, so a dose after breakfast is wasted, and eating within an hour after it mostly re-stores what it released. A 5 mg vial is about 16 days at 300 mcg, so a 12-week run is five vials, which is the point where most people should ask whether the money would do more elsewhere. The common mistakes: dosing fed, dosing at night with no activity, and running it outside a deficit.

The evidence, straight: there are no human trials of the plain fragment. Animal and lab work supports the idea that it mobilizes fat without raising IGF-1 or blood sugar. The closest human data is on AOD-9604, a stabilized version of the same fragment, which went through real obesity trials in the 2000s and produced weight loss that was statistically real but so small the company stopped developing it. The fragment and AOD-9604 are different products, so even that modest result cannot be borrowed directly. Older work on GH fragments is mixed on blood sugar, so the 'clean' story is a claim, not a finding. Not approved, and on the WADA banned list.

Skip it if you have real weight to lose: semaglutide, tirzepatide or retatrutide will do in a month what this will not do in a year. Skip it if you are not already dieting and training, because it has nothing to amplify. If you want the same idea with the human safety data attached, AOD-9604 is the one that was actually studied. For a different angle on stubborn fat, 5-Amino-1MQ works on a metabolic enzyme and L-Carnitine helps fat get burned once it is mobilized; both are cheap enough to try alongside.

What people use it for

Safety, in brief

The full picture — stop signs and who should talk to a doctor first — is on the dosing guide.

Sources

The labels and studies behind this page. Each link opens the original on PubMed, DailyMed or ClinicalTrials.gov.

1. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out miceHeffernan et al., Endocrinology 2001 · Study
2. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormoneNg et al., Horm Res 2000 · Study