HGH Fragment 176-191 vs Amycretin
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Frag 176-191, HGH Frag
HGH Fragment 176-191 is exactly what it sounds like: a short tail-end piece of the human growth hormone molecule, amino acids 176 through 191. The idea was to keep the fat-burning part of growth hormone while ditching the parts that raise blood sugar and IGF-1. The bare fragment has never been tested in a controlled human trial. Its modified cousin, AOD-9604, did go through real obesity trials, and the blunt result is that it was very safe but did not produce meaningful weight loss. It is banned in sport by WADA.
Also: Zenagamtide, NNC0487-0111
Amycretin is Novo Nordisk's single-molecule agonist of both the GLP-1 and amylin receptors, developed as a once-weekly injection and a once-daily pill. Early trials produced some of the biggest weight-loss numbers seen with any obesity drug so far, and the injectable version entered phase 3 (the AMAZE program) in 2026. It is not approved anywhere, and everything known about it comes from company-run trials of up to 36 weeks.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
- Amycretin has stronger research evidence (Human Trials) compared to HGH Fragment 176-191 (Animal Studies).
Detailed Comparison
| Attribute | HGH Fragment 176-191 | Amycretin |
|---|---|---|
| Category | Weight Loss | Weight Loss |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | This fragment is the C-terminal portion of growth hormone, the segment researchers linked to its effects on fat metabolism. The cleanest early data (Wu and Ng, 1993, rat fat tissue) found the closely related hGH 177-191 matched whole growth hormone at blocking new fat formation (antilipogenic) but had no significant direct fat-breakdown (lipolytic) effect. Later mouse work with AOD-9604 reported more fat oxidation, apparently without binding the growth hormone receptor itself. That is the selling point: because it does not act on the GH receptor, it does not raise IGF-1, does not promote tissue growth, and does not impair glucose handling the way full growth hormone can. Some research points to beta-3 adrenergic signaling in fat tissue, but the human mechanism is not nailed down. | Amycretin hits two appetite systems at once. The GLP-1 side slows stomach emptying, boosts insulin release after meals, and dampens appetite in the brain, the same biology behind semaglutide. The amylin side mimics a hormone your pancreas releases alongside insulin, which acts on the brainstem to make you feel full sooner and also curbs glucagon after eating. Novo combined these two signals in one molecule rather than mixing two drugs (which is what its CagriSema combination does). The bet is that the two pathways add together, giving more weight loss than either alone. That idea fits the early data, but it has not yet been tested head-to-head against semaglutide or tirzepatide in a large trial. |
| Common Dosing | 250-500 mcg daily 1-2x daily, fasted | Trial doses of 1.25-40 mg once weekly (injection) Once weekly (injection) or once daily (tablet) |
| Administration | Subcutaneous injection on empty stomach | Subcutaneous injection once weekly, or oral tablet once daily (separate formulations) |
| Typical Duration | 8-12 weeks | 20-36 weeks in published trials; phase 3 runs longer |
| Best Time to Take | Before bed or morning (fasted) | Same day each week (injection); trial protocols set timing for the tablet |
Possible Side Effects May vary by individual |
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| Research Summary | The animal data looked promising and the human data deflated it, which is the whole story here. One caveat up front: every human result below comes from AOD-9604, the tyrosine-capped version, not the bare 176-191 fragment sold today. In obese mice (Endocrinology, 2001), both growth hormone and AOD-9604 reduced body-weight gain and increased fat oxidation, without the blood-sugar problems of full GH. A small 12-week phase 2 human study of AOD-9604 generated the early headline, with the 1 mg group losing modestly more weight than placebo. But the larger, better-powered phase 2b trial of roughly 500 obese adults over 24 weeks failed to show a significant weight-loss advantage over placebo, and the developer abandoned obesity development. What survived is the safety record: across about six trials and roughly 900 people, AOD-9604 was as well tolerated as placebo, with no IGF-1 rise and no glucose effects (Journal of Endocrinology and Metabolism, 2013). So the closest human data say safe, and not a meaningful fat-loss drug. | Two early trials were published in The Lancet in June 2025. In the subcutaneous phase 1b/2a trial (125 adults with overweight or obesity), the estimated weight loss assuming full adherence was 24.3% at 60 mg over 36 weeks and 22.0% at 20 mg over 36 weeks, versus roughly flat weight on placebo, with no plateau by the end of treatment. A separate phase 1 trial of the oral tablet (144 people, 12 weeks) showed up to 13.1% loss at the highest dose. In November 2025 Novo reported a 36-week phase 2 trial in 448 adults with type 2 diabetes: up to 14.5% weight loss with weekly injections (2.6% on placebo), up to 10.1% with the daily pill, and HbA1c drops of up to 1.8 points. Side effects were mostly gastrointestinal, dose-related, and mild to moderate. Novo moved both forms into phase 3; AMAZE 1 (weekly injection at 1.25, 5, 20 or 40 mg versus placebo, about 1,150 people without diabetes) is registered as NCT07339423 with completion expected in 2029. Honest caveats: the headline numbers come from small trials using an efficacy estimand that assumes everyone stayed on drug, and long-term safety is unknown. |
Frequently Asked Questions: HGH Fragment 176-191 vs Amycretin
What is the difference between HGH Fragment 176-191 and Amycretin?
HGH Fragment 176-191 is a weight loss peptide that hgh fragment 176-191 is exactly what it sounds like: a short tail-end piece of the human growth hormone molecule, amino acids 176 through 191. the idea was to keep the fat-burning part of growth hormone while ditching the parts that raise blood sugar and igf-1. the bare fragment has never been tested in a controlled human trial. its modified cousin, aod-9604, did go through real obesity trials, and the blunt result is that it was very safe but did not produce meaningful weight loss. it is banned in sport by wada. Amycretin is a weight loss peptide that amycretin is novo nordisk's single-molecule agonist of both the glp-1 and amylin receptors, developed as a once-weekly injection and a once-daily pill. early trials produced some of the biggest weight-loss numbers seen with any obesity drug so far, and the injectable version entered phase 3 (the amaze program) in 2026. it is not approved anywhere, and everything known about it comes from company-run trials of up to 36 weeks. The main differences lie in their mechanisms of action and clinical applications.
Which is better, HGH Fragment 176-191 or Amycretin?
Neither is universally "better" - the choice depends on your specific goals. HGH Fragment 176-191 is typically used for weight loss purposes, while Amycretin is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can HGH Fragment 176-191 and Amycretin be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using HGH Fragment 176-191 and Amycretin together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.