AOD-9604: hGH Fragment 176-191 Analogue for Fat Loss
Modified fragment of human growth hormone marketed as a fat-loss peptide. Human trials did not support efficacy; widely sold in grey market.
👥🐀 Human + animal
- Full name
- AOD-9604 (Tyr-hGH 177–191)
- Class
- hGH C-terminal fragment analogue
- Half-life
- ~30 minutes
- Route
- Subcutaneous injection; oral forms marketed but poorly absorbed
- Developer
- Metabolic Pharmaceuticals (discontinued)
- Regulatory status
- No approval; TGA “Listed” in Australia as cosmetic ingredient; WADA-banned
What it is
AOD-9604 is a synthetic analogue of the C-terminal fragment of human growth hormone (residues 176–191) with an added tyrosine residue. It was developed on the hypothesis that this fragment retains the lipolytic activity of full-length hGH without growth-promoting effects.
How it works
In rodents, hGH 176-191 fragment increased fat mobilisation and β-adrenergic sensitivity in adipose tissue without activating the GH receptor. This separation of lipolytic from growth-promoting effects was the commercial promise.
In humans, however, the fragment did not activate human GH receptor signalling, and convincing effects on body composition have not been demonstrated.
What the research shows
Phase 2 human trials were disappointing; the compound was discontinued as an obesity drug.
Ng F.M. et al. (1994) — rodent lipolysis
Ng F.M. et al., Horm Res 1994;42:66–72. 🐀 Animal
In ob/ob mice and lean rats, hGH 176-191 fragment increased fat loss and lipolytic markers.
These pre-clinical findings drove commercial development by Metabolic Pharmaceuticals.
Limitations: Rodent data only; hGH receptor biology differs markedly between species.
Heffernan MA et al. (2001) — human Phase 2
Heffernan M.A. et al., Eur J Endocrinol 2001;144:491–498 (precursor studies). 👥 Human studies
Obese human volunteers received AOD-9604 at various doses for 12 weeks.
No statistically significant difference in body weight or fat mass vs placebo. The programme was halted.
Limitations: Definitive negative outcome; drug was never approved for weight loss.
Safety and limitations
Short-term human safety was benign: no significant changes in IGF-1, glucose, or insulin in Phase 1/2 studies. However, peptides sold as “AOD-9604” in the grey market are unregulated and often mislabelled.
WADA prohibits use in sport as a GH-related peptide. Claims of safety do not justify claims of efficacy — the trials showed no benefit.