AOD-9604: What It Is and What the Trials Found

The first published metabolic study of AOD-9604 treated obese Zucker rats with an oral dose of 500 micrograms per kilogram of body weight daily for 19 days. Treated animals gained 15.8 g on average, versus 35.6 g in untreated controls — more than a 50% reduction in weight gain — alongside increased lipolytic (fat-breakdown) activity in their adipose tissue. Using euglycemic clamp testing, the same study found no adverse effect on insulin sensitivity, in contrast to chronic treatment with intact hGH.^[1]

A follow-up study in obese mice, including mice genetically engineered to lack the beta-3 adrenergic receptor (beta3-AR), ran 14 days of chronic treatment with either hGH or AOD-9604. Both reduced body weight and fat and increased beta3-AR expression in fat tissue, but the researchers concluded the lipolytic action of both compounds was not directly mediated through that receptor: beta3-AR-knockout mice did not lose weight on chronic treatment, yet a single acute dose of AOD-9604 still raised their energy expenditure. The mechanism, in other words, is not fully mapped.^[2]

An early randomized, placebo-controlled human trial ran for 12 weeks. At a 1 mg per day dose, participants receiving AOD-9604 lost an average of 2.6 kg, against 0.8 kg on placebo. Notably, the effect was not dose-dependent: a 10 mg per day arm in the same programme showed a smaller reduction than the 1 mg dose, an inconsistency that is itself part of the published record rather than a detail marketing materials tend to repeat.^[3]

The trial that decided AOD-9604's fate was larger: a pivotal, placebo-controlled Phase IIb trial in 536 obese adults, run over 24 weeks. It did not demonstrate statistically significant weight loss against placebo. Metabolic Pharmaceuticals terminated the compound's obesity development programme in 2007 as a direct result — after Phase IIa human testing had been underway since at least 2002.^[3][5]

A pooled safety analysis covering six randomized, double-blind, placebo-controlled AOD-9604 trials reported that the compound had no measurable effect on serum IGF-1 — consistent with the idea that it does not act through the same pathway as intact hGH. Oral glucose tolerance testing found no negative effect on carbohydrate metabolism, unlike hGH itself. Blood samples were screened for anti-AOD-9604 antibodies, and none were detected in the patients assayed.^[4]

Across all six trials, the same analysis reported no withdrawal and no serious adverse event attributable to AOD-9604, describing its tolerability profile as indistinguishable from placebo and free of the adverse effects associated with full-length hGH treatment.^[4]

No. AOD-9604 has no FDA approval and no EMA marketing authorisation as a medicine for obesity, or for anything else. Its only obesity development programme ended with the 2007 Phase IIb result described above, and no successor programme has produced an approved drug.^[3]

In the United States, AOD-9604 has separately been reviewed as a candidate bulk substance for pharmacy compounding, and nominators later withdrew that nomination. The FDA's own listing states that compounded drugs containing AOD-9604 'may pose significant risk for immunogenicity for certain routes of administration,' that the agency has identified 'no, or only limited, safety-related information,' and that it has identified serious adverse events that may be associated with AOD-9604, though causality is not established. That FDA language sits in tension with the sponsor-funded trial safety data above — a gap between a small, controlled trial programme and the far less controlled real-world market this section covers next.^[7]

The World Anti-Doping Agency names AOD-9604 explicitly on its Prohibited List. Under section S2.2.3, covering 'Growth hormone (GH), its analogues and fragments,' the list gives 'growth hormone fragments, e.g. AOD-9604 and hGH 176-191' as examples — placing it in the category of substances prohibited at all times, in and out of competition, for any athlete subject to the Code.^[6]

Anti-doping laboratories have published validated methods for detecting AOD-9604 in urine, and the compound has turned up in seized, unregulated peptide preparations — including a case report on vials confiscated by Belgian authorities and material identified in the United States. That circulation outside any approved supply chain is a separate problem from the compound's failed obesity trial, but the two are related: a compound with no approved medical use still finds a market once it acquires an online reputation as a fat-loss shortcut.^[8][9]

AOD-9604 is a 16-amino-acid fragment that does not bind the growth hormone receptor the way intact hGH does; full-length recombinant hGH is the complete 191-amino-acid hormone, still an active pharmaceutical class with defined authorisations for specific deficiency indications in adults and children. Readers who want that fuller comparison — the hormone itself against compounds that prompt the body to release more of its own — should read our dedicated guide rather than treat this page as covering that ground twice.

Peptyds does not sell AOD-9604. This page exists because the name is heavily searched and widely misrepresented online as a proven fat-loss shortcut. The honest, sourced answer is that its own obesity programme failed a pivotal trial, it holds no medicine approval anywhere, and it is a named, banned substance in competitive sport — not a reason to buy it, and not something Peptyds lists for sale.^[3]