01 What is AOD-9604?
In plain English.
AOD-9604 is a lab-made peptide copied from the tail end of human growth hormone, specifically the last 16 amino acids of the molecule, residues 176 to 191. In the 1990s a group at Monash University proposed that this small "lipolytic" tail carried most of growth hormone's fat-burning effect without its growth-promoting side. Metabolic Pharmaceuticals, an Australian biotech, licensed the work and developed AOD-9604 as a candidate anti-obesity drug.
That development programme is over. The drug was taken through human clinical trials, those trials did not meet their endpoints, and Metabolic abandoned the obesity indication. The vials sold online today are the leftover idea, the peptide its own developer tried and failed to turn into a medicine.
02 How it works
The simple version, then the science.
In the original mouse work, AOD-9604 increased fat breakdown (lipolysis) and reduced fat storage (lipogenesis), apparently without the blood-sugar and growth effects of the full growth hormone molecule. The pitch was elegant: a "GH-like fat-burner" that wouldn't cause insulin resistance or acromegaly. In humans, that pitch did not hold up at the clinical-endpoint level.
Go deeper · the proposed mechanism
Ng and colleagues at Monash mapped the lipolytic activity of growth hormone to its C-terminal domain and proposed AOD-9604 as a stabilised mimic. In rodents, Heffernan et al. reported reduced body weight and increased fat oxidation after chronic treatment with the fragment, with effects that appeared partly independent of the β3-adrenergic receptor. The proposed mechanism involves upregulation of β3-AR expression and direct stimulation of lipolysis in adipocytes. None of this has been confirmed at clinically meaningful magnitudes in humans.
03 What it's used for
Each use graded by how strong the evidence actually is.
- LimitedObesity / weight lossThe original indication. Phase 2 trials in obese adults did not show a clinically meaningful weight-loss advantage over placebo, and Metabolic Pharmaceuticals halted the obesity programme. Despite this, fat loss remains the dominant online marketing claim.
- PreclinicalLipolysis & fat oxidationReproducible effects in rodent studies (Heffernan, Ng et al.), increased fat oxidation, reduced body weight in obese mice. Read-across to humans was the basis of the failed trials.
- PreclinicalCartilage repair / osteoarthritisA 2015 rabbit study (Kwon & Park) reported that intra-articular AOD-9604, especially with hyaluronic acid, improved cartilage outcomes in a collagenase-induced osteoarthritis model. Animal only; no human trials.
- AnecdotalBody recomposition in gym communitiesMarketed alongside CJC-1295/ipamorelin stacks as a "fat-burning" peptide. Not supported by controlled human data.
04 What the evidence says
AOD-9604's evidence base is unusual: it has more animal data than most research-chemical peptides, and it has actual human trials, which is rare in this space, but those human trials were unflattering. The rodent literature (Ng 2000; Heffernan 2000, 2001) is consistent: the fragment increases fat oxidation and reduces weight in obese mice. The translation problem hit in humans. Metabolic Pharmaceuticals progressed AOD-9604 through Phase 1 and into Phase 2 obesity trials in the mid-2000s; the compound was well-tolerated, but the weight-loss signal versus placebo was not clinically meaningful, and Metabolic discontinued the obesity programme. No Phase 3 trial was ever run. A small later study (Kwon & Park, 2015) suggested possible cartilage-repair effects in rabbit knees, which is where some of the modern "joint" marketing comes from, but again, no human trials. Honest summary: a drug candidate that did not work as advertised, kept alive by the research-chemical market.
05 Dosing & administration
Reported in the literature, information not advice.
Because the obesity programme failed and AOD-9604 is not an approved medicine, there is no clinically sanctioned dose. The trial literature used both oral and subcutaneous formulations in the milligram range. Online vendors describe daily subcutaneous microgram-to-milligram regimens, but these are not based on a successful clinical protocol and the purity of research-grade vials is unregulated. Anyone considering use should speak to a clinician.
06 Side effects & safety
Across Metabolic Pharmaceuticals' clinical programme, AOD-9604 was reported as well-tolerated, its problem was efficacy, not acute safety. That said, long-term safety in humans is genuinely unknown: no large trial was ever run because the drug did not work, and the people now injecting it are not being monitored. Reported short-term effects in users include injection-site reactions and mild GI upset. Because the fragment is derived from growth hormone, theoretical concerns around insulin sensitivity, IGF-1 signalling and any cancer history are reasonable, even though the trials did not flag them at the doses tested. Products sold as "AOD-9604" are unregulated research chemicals, purity, identity and contamination cannot be assumed. People who are pregnant, breastfeeding, immunocompromised, taking other medicines, or with a history of cancer should be especially cautious.
07 Where to buy (research use only)
Vetted on quality and transparency, not an endorsement to use.
08 Legal & regulatory status
- UKNot licensed as a medicine. Sold only as a "research chemical", not for human use.
- USNot FDA-approved as a drug. Not on the FDA's 503A/503B lists of bulk substances permitted for compounding. Sale for human use is not authorised.
- EU / CANNo approved human medicine containing AOD-9604. Sale for human use is unlawful in most jurisdictions; "research use only" framing is standard.
- AustraliaDeveloped in Australia but never approved as a medicine. The TGA has at points listed it as a permitted compounding ingredient, but it remains an unapproved substance.
- Sport (WADA)Falls under S2, Peptide Hormones, Growth Factors, Related Substances and Mimetics, as a growth-hormone-derived fragment. Prohibited at all times in tested sport.
09 Clinical studies & research
Primary sources. Read the science yourself.