AOD-9604

What is AOD-9604?

AOD-9604, short for Anti-Obesity Drug 9604, is a modified fragment of human growth hormone. It consists of amino acids 177 to 191 from the tail end of the growth hormone molecule, with an extra tyrosine added to make it more stable. It was developed in Australia as a fat-loss drug by Metabolic Pharmaceuticals, building on university research into which part of growth hormone drives fat breakdown.¹

By the early 2000s it had reached human trials, with phase IIa studies underway by 2002.¹ In a 2006 review of obesity drugs in development it sat alongside GLP-1 drugs and other candidates as a growth hormone fragment intended to increase fat breakdown.⁴

It did not succeed. A larger phase IIb trial in adults with obesity did not show weight loss beyond placebo, and development for obesity was dropped. Despite that, AOD-9604 is still widely marketed for fat loss and, more recently, for joint and cartilage repair, usually on the strength of animal studies.

How AOD-9604 works

Growth hormone has many jobs. It helps build muscle and bone, raises blood sugar and promotes fat breakdown. Researchers hoped that a small piece of the hormone could keep only the fat-burning part, without growth hormone's effects on blood sugar or on IGF-1, the growth factor linked to many of growth hormone's other actions. AOD-9604 was designed as that piece.

In preclinical studies, AOD-9604 stimulated lipolysis and inhibited lipogenesis in fat tissue of rodents, and, according to the developer's studies, it did so without raising IGF-1 or impairing glucose tolerance. The exact receptor or pathway it acts through in fat cells has never been fully established. Its plasma half-life is short, roughly half an hour after injection. Some recent reviews group it with growth hormone secretagogues, but it does not stimulate growth hormone release and was specifically designed to avoid IGF-1 effects.

What the research shows on AOD-9604

The human evidence is the most important part of this story, and it is negative for the main claim. AOD-9604 went through several human trials for obesity, including the phase IIa work noted above.¹ The definitive test was a phase IIb trial in adults with obesity, which did not separate from placebo on weight loss. The developer ended the obesity program after that result. Full peer-reviewed publication of the human trial data has been limited, which makes independent assessment harder.

The positive evidence is almost entirely in animals. Rodent studies showed reduced body fat and increased fat burning. Later animal work explored cartilage repair after injection into joints, which underlies the current marketing for joint health. Reviews of peptides in orthopedics note that although preclinical findings are promising, there is a current lack of clinical trials to support use.²

A 2026 review of unapproved peptides used in sports medicine, which covered AOD-9604, found that many show favorable outcomes in animals but that rigorous human safety data are scarce and the potential for harm is real. The same review discussed how the placebo effect and social media amplify perceived benefits.³

Why might a compound that burned fat in rodents fail in people? Several explanations are possible. Rodents have proportionally more metabolically active fat and respond more strongly to many fat-burning signals. The short half-life may mean the drug is cleared before it has a lasting effect. And a modest increase in fat breakdown does not lead to weight loss if appetite and calorie intake adjust to compensate.

Put simply, the one question that was tested properly in humans, whether AOD-9604 causes weight loss, got a no.

Studied for: Fat loss research, Investigated for osteoarthritis.

AOD-9604 reference data

AOD-9604 dosage in published research

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How AOD-9604 is used in practice

AOD-9604 is sold online as a research peptide, usually as powder in vials for injection, and sometimes as oral or nasal products. It has been offered by some anti-aging and weight-loss clinics in the US, typically as a daily injection taken on an empty stomach. It is not FDA approved, and US compounding pharmacies face restrictions on using it.

Products from research-chemical vendors have no regulatory oversight. Identity, purity and sterility are not verified, and peptide fragments are easy to mislabel or substitute. Oral products face an additional problem. Peptides are largely broken down in the gut, and no human evidence shows that oral AOD-9604 reaches meaningful blood levels.

For athletes, AOD-9604 is a known target of anti-doping work. Laboratories have developed detection methods for it alongside other non-approved peptides classified as doping agents.⁵

AOD-9604 risks and side effects

In the human trials, AOD-9604 was generally reported as well tolerated, which is one consistent finding. Commonly reported side effects in use are injection-site reactions, headache and transient fatigue.

That trial experience has limits. The studies used pharmaceutical-grade product under controlled conditions, for months rather than years. Long-term safety, effects in pregnancy, effects on joints when injected locally, and interactions with other drugs are not well characterized. People using gray-market products also take on the risks of contamination, wrong dosing and nonsterile injection, including infection.

Sports medicine authors have warned that the lack of rigorous human data for unapproved peptides like AOD-9604 leaves real potential for harm.³ A further risk is indirect, and it is easy to overlook. Time and money spent on an ineffective product can delay treatments that work.

Reported side effects

Alternatives to AOD-9604

For weight loss, FDA-approved options with strong human evidence include semaglutide (Wegovy), tirzepatide (Zepbound) and liraglutide (Saxenda), along with phentermine-topiramate (Qsymia), naltrexone-bupropion (Contrave) and orlistat. Bariatric surgery is an option for severe obesity. Tesamorelin (Egrifta) is approved specifically to reduce excess abdominal fat in people with HIV-associated lipodystrophy.

For joint pain and osteoarthritis, evidence-based approaches include exercise therapy and physical therapy, weight loss, topical or oral NSAIDs used appropriately, corticosteroid injections for short-term relief and joint replacement for advanced disease. Other injectables such as hyaluronic acid and platelet-rich plasma have mixed evidence but more human data than AOD-9604.

Questions for a clinician

• What evidence applies to my situation, and at what level?
• What established alternatives should I consider first?
• What monitoring would be necessary, and how often?
• Can this be prescribed at all where I live, or only sold for research?