History

AOD-9604 was developed in the 1990s at Monash University in Melbourne, Australia, and licensed to the spin-off Metabolic Pharmaceuticals. Researchers isolated the fat-reducing C-terminal region of growth hormone (residues 176-191), aiming for fat breakdown without growth or insulin-resistance effects. It advanced through human obesity trials, but a Phase IIb study (around 2007, 500+ subjects, 24 weeks) failed to beat placebo on weight loss, ending its development as a drug. It was later repositioned toward food and supplement use via a GRAS pathway, with no FDA drug approval.

AOD-9604 is a synthetic peptide once developed as an anti-obesity drug. It is now sold widely as a “fat-loss peptide,” but the human trials behind it are small, short, and ultimately disappointing.

What it is

AOD-9604 (“Anti-Obesity Drug 9604”) is a synthetic fragment of human growth hormone (hGH), corresponding to the C-terminal region (amino acids 176-191) with an added tyrosine to help stabilize it. The idea, developed at Monash University and Metabolic Pharmaceuticals in Australia in the 1990s, was to isolate growth hormone’s fat-burning action while leaving out its broader hormonal effects. In the company’s trials it did not appear to raise IGF-1 or activate the growth hormone receptor the way full hGH does.

The claims

Marketing positions AOD-9604 as a peptide that triggers fat breakdown (lipolysis) and blocks new fat storage (lipogenesis) without affecting appetite, blood sugar, or growth-hormone pathways. Vendors and clinics frequently describe it as a clinically studied, “GRAS-approved” fat-loss aid. As explained below, “GRAS” is a narrow food-ingredient designation, not drug approval and not proof that it works for fat loss.

What the evidence actually shows

The mechanism has real laboratory support: rodent and cell studies (for example, Heffernan and colleagues in Endocrinology, 2001) reported reduced body weight and fat mass with both hGH and AOD-9604. In that work the lipolytic effect appeared to operate largely independently of the beta-3 adrenergic receptor, so the exact pathway in humans remains uncertain.

Human data are weaker than the marketing implies. AOD-9604 went through a series of placebo-controlled trials in obese adults. An early 12-week study reported modest weight loss on a 1 mg/day oral dose (roughly 2.6 kg versus about 0.8 kg on placebo). But the larger, pivotal Phase IIb trial — the one that mattered for approval, with several hundred participants — did not beat placebo by a statistically significant margin. Metabolic Pharmaceuticals halted development of AOD-9604 for obesity in 2007. In short: encouraging biology, a small early signal, and a definitive failure in the trial designed to prove it worked. Claims about joint, cartilage, or anti-aging benefits rest on even thinner evidence.

Legal and regulatory status

As of June 2026, AOD-9604 is not an approved drug anywhere — not by the FDA, the EMA, or Australia’s TGA. It did receive a GRAS (Generally Recognized as Safe) notification for use as a food ingredient, but that is a narrow food-additive pathway; it is not drug approval and not evidence of effectiveness for fat loss.

For compounding pharmacies, the picture tightened recently. At its December 4, 2024 meeting, the FDA’s Pharmacy Compounding Advisory Committee reviewed AOD-9604 (free base and acetate), and the FDA proposed against adding it to the 503A bulks list, citing limited safety information and concerns about immunogenicity and peptide-related impurities. Practically, that means it is not a legitimately compoundable drug in the U.S. In sport, the World Anti-Doping Agency prohibits AOD-9604 at all times under category S2 (peptide hormones, growth factors, related substances and mimetics).

Safety

Across the company’s controlled trials, AOD-9604 was generally reported as well tolerated over a few months, without the IGF-1 increases or glucose problems seen with full growth hormone. That is reassuring but limited: the trials were short, much of the dosing studied was oral rather than the injections sold today, and there are no long-term human safety data. The FDA specifically flagged immunogenicity and product-impurity risks. Material sold online is unregulated and may differ in purity and dose from anything that was tested. Nothing here is medical advice.

Bottom line

AOD-9604 has a plausible mechanism and a real, if modest, early human signal — but the trial built to confirm a fat-loss benefit failed, development was abandoned, and it remains unapproved as a drug everywhere. It is best understood as a discontinued drug candidate now sold ahead of its evidence.

Evidence grade: Preliminary human.

Sources

Heffernan M, et al. The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology, 2001.
The effect of AOD9604 on weight loss in obese adults: results of a randomized, double-blind, placebo-controlled, multicenter study (Diabetes, Obesity & Metabolism).
FDA, December 4, 2024 Meeting of the Pharmacy Compounding Advisory Committee.
WADA, The Prohibited List (S2: Peptide Hormones, Growth Factors, Related Substances and Mimetics).