AOD-9604

AOD-9604 is a synthetic 16-amino-acid peptide corresponding to residues 177–191 of the C-terminal region of human growth hormone (hGH), with a tyrosine residue added at the N-terminus (sequence: Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe). The two cysteine residues form an intramolecular disulfide bridge. It was developed in the 1990s by researchers at Monash University, Australia, on the hypothesis that the lipolytic activity of hGH could be isolated to its C-terminal region, separated from the growth-promoting and glucose-metabolising effects of the intact hormone. AOD-9604 underwent six randomised, double-blind, placebo-controlled clinical trials between the late 1990s and 2007, conducted primarily in Australia by Metabolic Pharmaceuticals Pty Ltd (a Monash University spin-out). These trials enrolled a total of approximately 893 subjects. While small Phase 2a oral studies showed a modest signal (~1.8–2.6 kg more weight loss vs placebo), the pivotal Phase 2b OPTIONS study — a 536-subject, 24-week randomised trial across 16 Australian sites — failed to meet its primary endpoint of weight loss at 12 weeks at any oral dose tested (0.25 mg, 0.5 mg, or 1.0 mg daily). The obesity drug programme was discontinued in 2007 and no Phase 3 trial was conducted. Following the clinical programme, Metabolic Pharmaceuticals pursued FDA GRAS (Generally Recognized as Safe) designation for AOD-9604 as a food ingredient, which was granted circa 2014 at up to 1 mg per person per day by oral route. This GRAS status pertains to oral food use and says nothing about efficacy or the safety of other routes. AOD-9604 is not approved as a drug anywhere in the world. It is explicitly named on the WADA Prohibited List under Section S2 (growth hormone fragments) and is prohibited at all times in competitive sport. Products are sold as research-use-only material.