Overview
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In plain language
AOD-9604 is a lab-made peptide based on a small piece of human growth hormone, the piece researchers thought might be responsible for fat burning. It is 16 amino acids long.
It was developed in Australia as a possible weight-loss drug. In larger human trials, it did not produce meaningful weight loss compared with placebo, and development as a medicine stopped. It is not an FDA-approved drug.
For students
AOD-9604 is a modified fragment of human growth hormone residues 177–191 with an added N-terminal tyrosine (often written hGH 176–191), about 1,815 Da. The idea was to keep the lipolytic activity reported for the C-terminal region of GH without its effects on growth, IGF-1 or blood glucose.
Animal studies reported increased fat breakdown and reduced fat gain in obese rodents. Human trials in the 2000s, including a larger 12-week trial, failed to show clinically meaningful weight loss versus placebo, and the program was discontinued. It is graded Controlled trials because placebo-controlled human studies exist, even though they were negative.
For researchers and instructors
Rationale. Early work suggested the hGH C-terminal fragment stimulates lipolysis and inhibits lipogenesis in adipocytes without binding the GH receptor in a growth-promoting way or raising IGF-1.
Human evidence. Phase 2 trials by Metabolic Pharmaceuticals reported good tolerability but no significant weight loss over placebo in the pivotal study, after which obesity development ended.
Regulatory and sport. Not FDA-approved. WADA lists it among prohibited substances. Products sold online have unverified identity and purity.
Teaching point. A useful case study in why encouraging rodent efficacy and plausible mechanism do not guarantee clinical benefit.
Molecular identity
- Amino acids
- 16
- Molecular weight
- ~1,815 Da
- Formula
- Form-dependent
- Sequence
- Modified hGH fragment 176–191
Origin and history
AOD-9604 (“Anti-Obesity Drug 9604”) was developed in the 1990s by Frank Ng and colleagues at Monash University in Melbourne. They found that the fat-burning activity of growth hormone sits in its tail end, so they made a fragment of amino acids 176–191 with an extra tyrosine, hoping to keep the fat loss without growth hormone’s other effects.
The Australian company Metabolic Pharmaceuticals took it into human trials. In 2007 a large Phase 2b trial found no meaningful weight loss compared with placebo, and the obesity program was dropped. It resurfaced in 2013 at the center of the Essendon Football Club doping investigation in Australia, and WADA confirmed it is prohibited.
Key people
- Frank NgBiochemist, Monash University, Melbourne
Timeline
- 1990s
Monash University develops the hGH 176–191 fragment
- 2000
Early metabolic studies published
- 2007
Phase 2b obesity trial fails; development stops
- 2013
Named in the Essendon doping investigation
- Today
Not FDA-approved
See every peptide on one history timeline.
Human evidence
Human obesity trials have not established convincing clinical benefit for weight loss.
Study exact analogue and formulation; distinguish trial outcomes from preclinical hypotheses.
Explore original publications and distinguish preclinical findings from controlled human evidence.
Safety and regulatory status
See every compound on the regulatory tracker.
Not FDA-approved for human therapeutic use.
Product identity, purity, sterility, and endotoxin testing address different risks. This profile is educational and does not provide treatment guidance.
Sources
Hernandez Gener, E. (2026, November 7). AOD-9604: molecular data, research history and evidence. VALREXA Biosciences. https://valrexa.com/peptides/aod-9604.html
APA style · Last reviewed November 7, 2026 · Our editorial standardsLast reviewed November 7, 2026. Trial and regulatory status can change; confirm in the linked registries. This profile is educational and is not medical advice, a treatment recommendation, or dosing or sourcing guidance. Report an error · Corrections policy