Fragment 176-191
HGH Fragment 176-191 — Growth Hormone Fat-Burning Fragment
What is Fragment 176-191?
HGH Fragment 176-191 is identical in sequence to AOD-9604 — it is the C-terminal fragment of human growth hormone comprising amino acids 176 through 191. The two names refer to the same compound with different naming conventions: AOD-9604 was the pharmaceutical development name used by Metabolic Pharmaceuticals, while Fragment 176-191 is the biochemical description used in research literature and many supplier contexts.
Fragment 176-191 activates fat cell beta-3 adrenergic receptors to stimulate lipolysis (fat breakdown) and inhibits lipogenesis (new fat formation) — the same dual mechanism as AOD-9604. It does not bind to the insulin-like growth factor receptor, does not affect blood glucose, and does not produce anabolic or growth effects of full HGH. The fat-specific receptor mechanism makes it a targeted fat oxidation agent.
Research Evidence
Multiple animal studies demonstrate significant reduction in body fat mass and increased fat oxidation without affecting lean mass or glucose metabolism. Consistent with AOD-9604 data (same compound).
Phase 1/2 clinical trial data under the AOD-9604 designation established human safety profile. Efficacy in humans was modest and inconsistent across trials.
Evidence grades: Gold = RCT human data · Silver = consistent animal/human data · Bronze = limited or preliminary
Dosing Protocols
Reconstitution Guide
| Vial Size | BAC Water | Concentration | Target draw |
|---|---|---|---|
| 2 mg | 2 ml | 1 mg/ml | 250mcg = 25 units |
| 5 mg | 4 ml | 1.25 mg/ml | 250mcg = 20 units |
Frequently Asked Questions
Is Fragment 176-191 the same as AOD-9604?
Yes — they are the same compound with different names. AOD-9604 (Anti-Obesity Drug 9604) was the pharmaceutical development name used by Metabolic Pharmaceuticals in their obesity clinical trials. Fragment 176-191 (or HGH Frag 176-191) is the biochemical name describing the amino acid sequence. Same molecule, same mechanism, same dosing.
Does Fragment 176-191 affect IGF-1 or blood sugar?
No. Unlike full HGH, Fragment 176-191 does not bind the IGF-1 receptor, does not stimulate IGF-1 production, and does not affect blood glucose or insulin sensitivity. This is its key advantage over full HGH for fat loss — targeted lipolysis without metabolic disruption.
References
- [1]Heffernan MA, Thorburn AW, Fam B, et al. Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone fragment 176-191. Int J Obes Relat Metab Disord. 2001;25(10):1442-1449.
- [2]Ng FM, Sun J, Sharma L, et al. Conformational characterization of a novel bioactive fragment of human growth hormone. Protein Eng. 1990;3(8):669-675.
This profile was prepared using AI-assisted research synthesis. Citations are provided where applicable — verify with primary sources before clinical application.
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