Overview
AOD-9604 (Anti-Obesity Drug 9604) is a synthetic 16-amino acid peptide fragment corresponding to amino acids 176–191 of human growth hormone, with a stabilizing tyrosine substitution at the N-terminus. It was developed by Metabolic Pharmaceuticals Ltd. in Australia during the 1990s in collaboration with researchers at Monash University.
The hypothesis was elegant: isolate the fat-metabolizing domain of growth hormone while removing the regions responsible for IGF-1 elevation, insulin resistance, and tissue growth. In rodent models, this worked. AOD-9604 reduced body weight in genetically obese mice without the adverse metabolic effects of full-length growth hormone. The compound advanced into human trials.
The human trials failed. A Phase IIb study enrolling over 300 obese subjects over 24 weeks did not meet its primary endpoint of statistically significant weight loss compared to placebo. The effect size was clinically negligible — approximately 2.6 kg vs. 0.8 kg. Development was terminated in 2007. Despite this, AOD-9604 became one of the most widely marketed grey-market peptides, sold with fat-loss claims that its own clinical data does not support.
Dosage & Reconstitution
- Vial strength
- 5 mg
- BAC water added
- 3 mL
- Final concentration
- ~1.67 mg/mL
| Weeks | Dosage | Syringe units (U-100) |
|---|---|---|
| Weeks 1–4 | 0.3 mg | 18 units0.18 mL |
| Weeks 5–12 | 0.5 mg | 30 units0.3 mL |
FrequencyOnce daily, subcutaneous, in the morning before eating.
Note
For review — not established human dosing. The one human trial of AOD-9604 that reported an amount used an oral 1 mg capsule and did not beat placebo. The injectable week ranges and amounts in the chart follow a circulated research protocol, not that trial. The concentration strip above the chart is calculated from the vial and water volume and is correct.
Unverified — no cited human study establishes a subcutaneous frequency for AOD-9604.
AOD-9604's only human trial was oral — 1 mg a day in 300 adults with obesity, and it missed its primary endpoint at 24 weeks — so the subcutaneous amounts charted here are not the amounts that were studied, and they are flagged for review rather than presented as established dosing. Athena lists one strength: a 5 mg vial made up with 3 mL comes to about 1.67 mg/mL, so the 0.3 mg starting step is 18 units and the 0.5 mg step is 30 units, both inside a single 50-unit syringe. AOD-9604 is a fragment of human growth hormone that does not raise IGF-1, so findings reported for growth hormone itself do not carry across to it.
What this evidence establishes. AOD-9604 has been studied in humans, but the trial that reported a dose used an oral formulation and did not reach its primary endpoint against placebo at 24 weeks. No injectable human dosing has been established in the published literature, so the reconstitution figures below are arithmetic only and are not tied to any studied injectable dose.
Sources: Phase IIa obesity trial (n=300), 2003–2005, reported on this site's AOD-9604 profile
For educational and laboratory research purposes only. It does not provide medical advice, dosing recommendations, or instructions for human or veterinary use. Syringe units assume a U-100 syringe, on which 1 mL is 100 units and a 50-unit syringe holds 0.5 mL.
Mechanism of Action
AOD-9604 targets adipose tissue metabolism through a mechanism distinct from full-length growth hormone:
Lipolysis Stimulation
Promotes breakdown of stored triglycerides in adipose tissue through β-adrenergic pathway interactions
Anti-Lipogenic
Inhibits formation of new fat — reducing both fat storage and fat cell proliferation in preclinical models
No IGF-1 Elevation
Does not activate the GH receptor or raise IGF-1 levels — distinguishing it from full-length growth hormone
Receptor-Independent
Fat-metabolizing effects appear to occur through a non-GH-receptor mechanism that remains incompletely characterized
Cartilage Interest
Post-failure pivot to cartilage repair applications led to TGA approval in Australia for osteoarthritis formulations
Glucose Neutral
No effect on blood glucose or insulin sensitivity observed in clinical trials — a safety advantage over full-length GH
Research Timeline
Contraindications & Safety Data
AOD-9604 has the most extensive human safety database of any discontinued research peptide — over 900 participants across six controlled trials. Adverse events were generally mild and comparable to placebo. However, efficacy failure and regulatory exclusion make the risk-benefit calculation unfavorable.
| Condition / Factor | Risk Level | Rationale |
|---|---|---|
| Active cancer or malignancy | MODERATE | Although AOD-9604 does not elevate IGF-1, the GH-fragment mechanism warrants caution in patients with active malignancy |
| Pregnancy / breastfeeding | HIGH | No reproductive toxicology data available for AOD-9604 in human pregnancy |
| Immunogenicity risk | MODERATE | FDA cites immunogenicity as a specific concern. Peptide impurities may trigger immune reactions |
| Hypoglycemia risk | LOW | Occasional reports of non-specific hypoglycemia in clinical trials, though glucose-neutral profile was generally confirmed |
| Cardiovascular conditions | LOW | No cardiovascular signals detected across 6 clinical trials and ~900 subjects |
| Use for weight loss | EVIDENCE FAILED | The compound failed its pivotal Phase IIb trial for this exact indication. Marketing claims for fat loss are not supported by the clinical data. |
| Grey-market sourcing | HIGH | Unregulated products carry contamination, mislabeling, and impurity risks on top of a compound that already failed its efficacy trial |
Regulatory Status
FDA: AOD-9604 is not FDA-approved for any therapeutic indication. Development was terminated in 2007 after Phase IIb failure. In December 2024, the FDA recommended against including AOD-9604 on the 503A bulks list for compounding, citing safety concerns including immunogenicity and insufficient long-term data. GRAS status as a food ingredient (2021) does not constitute therapeutic approval.
WADA: Classified as a prohibited substance under S2 (peptide hormones and growth factors). Banned in and out of competition.
TGA (Australia): Approved for use in specific cartilage repair formulations — not for fat loss or metabolic applications.
The critical point: AOD-9604 is the rare case where extensive human data exists — and the data shows the compound doesn't work for its marketed indication. Over 900 clinical trial participants. Six controlled trials. Primary endpoint failed. This is not a compound lacking evidence. It's a compound whose evidence is negative.
References (APA 7th Edition)
AOD-9604 Research Readiness Quiz
Test your understanding of AOD-9604's evidence base, regulatory status, and clinical trial history.