AOD-9604 is a lab-made fragment of human growth hormone, designed in Melbourne, Australia, to keep growth hormone’s fat-burning effect without its effects on growth or blood sugar.[17][7] It reduced weight gain in obese mice and rats,[6][7] but its largest human trial, in 502 adults, found no significant weight loss, and development for obesity stopped in 2007.[1] It is not approved by any regulator.[1]
This profile covers what AOD-9604 is, why its trials failed, how it compares with HGH Frag 176-191, side effects, doses studied and its legal status in the US and Australia.
What is AOD-9604?
AOD-9604 (“Anti-Obesity Drug 9604”) is a 16-amino-acid peptide: the last 15 amino acids of growth hormone (positions 177 to 191) with an extra tyrosine added at the start.[1] It was developed by Professor Frank Ng at Monash University in the 1990s and taken into trials by Metabolic Pharmaceuticals.[17][11]
How AOD-9604 works
In obese mice, both growth hormone and AOD-9604 increased fat burning and reduced weight gain. Unlike growth hormone, AOD-9604 did not raise blood sugar, did not bind the growth hormone receptor, and did not make cells multiply.[7] Experiments in mice lacking a key fat-cell receptor suggested its effect does not run directly through that receptor.[8]
One of the lead human investigators has suggested a reason it did not work in people: its longer-term effect in mice appeared to depend on a receptor that differs between mice and humans.[17]
AOD-9604 benefits: what the research shows
In animals
- Obese mice: the unmodified 177-191 fragment reduced weight gain and fat tissue mass.[10]
- Obese mice, by mouth: a closely related lab-made fragment (AOD-9401) given orally for 30 days slowed weight gain from day 16 onward without changing food intake. In lab dishes, it also increased fat breakdown in fat tissue taken from obese rodents and from people.[9]
- Obese rats: AOD-9604 by mouth cut weight gain by more than half over 19 days without harming insulin sensitivity.[6]
- Joints: in Korean rabbits with osteoarthritis, AOD-9604 injected into the knee with hyaluronic acid gave the best cartilage scores.[14]
In people
About 900 people took part in six company-funded human trials.[12]
- OPTIONS (phase 2b): 502 adults with obesity took 0.25 to 1 mg daily or placebo for 24 weeks alongside diet and exercise. There was no significant difference in weight loss at 12 or 24 weeks, and the company ended obesity development.[1]
- 12-week trial: in 300 adults, weekly weight loss was only slightly greater than with placebo, largest at the lowest dose and significant only in women. FDA found no full publication.[1]
- Lead investigator’s view: the researcher who led five of the six trials said the six-month study found no effect on weight.[17]
- Joints in people: there are no human osteoarthritis trials; the company described this work as preclinical.[15][1]
AOD-9604 vs HGH Frag 176-191
Both come from the end of the growth hormone molecule. AOD-9604 is the 177-191 fragment plus an added tyrosine; “Frag 176-191” refers to the unmodified fragment.[1] Many sellers and even some reviews use the names interchangeably.[31] Frag 176-191 has no human trials; the only primary study we found tested it in breast cancer cells in a lab in Saudi Arabia.[26] WADA bans both as growth hormone fragments.[19]
AOD-9604 vs tesamorelin
They are often compared for belly fat, but they work very differently. Tesamorelin makes the pituitary release more of the body’s own growth hormone and is FDA-approved after phase 3 trials showed it reduces deep belly fat in people with HIV. AOD-9604 is a fragment that does not raise growth hormone or IGF-1 and failed its obesity trials.[12][1]
AOD-9604 side effects and safety
From the company’s pooled safety report and FDA’s review:[12][1]
- Headache was the most common side effect, reported by 26% to 70% of participants across trials.
- Stomach effects such as diarrhea and gas, especially at higher oral doses.
- Injection studies: chest tightness, palpitations and euphoria were reported in short-term IV studies.[17]
- Serious events: in the 12-week trial, five people developed cancers or tumors, which investigators judged unrelated; FDA said there was too little detail to assess whether they were related.[1][12]
- No effect on IGF-1 or blood sugar, and no antibodies were found in the people tested.[12]
- Animal toxicology: a 2014 report found no signs of genetic damage in standard lab tests and judged it generally safe in rats given it by mouth for 6 months and monkeys for 9 months. Taken by mouth, it was absorbed and then broken down quickly in pigs. These were animal studies, not human safety data.[13]
- Product quality: FDA notes the peptide’s structure can degrade and clump, raising immune-reaction concerns.[1][3]
Long-term safety in people is unknown.[17]
AOD-9604 dosage: what has been studied
| Route | Doses studied in humans |
|---|---|
| IV | 25 to 400 mcg per kg as single doses[12] |
| By mouth, short term | 9, 27 or 54 mg for up to 7 days[12] |
| By mouth, 12 weeks | 1 to 30 mg daily[12] |
| By mouth, 24 weeks | 0.25 to 1 mg daily[12] |
| Injection under the skin | Never studied in humans[1] |
For converting milligrams to syringe units, see our peptide calculator.
AOD-9604 research around the world
- Australia: all the original animal research and human trials came from Monash University and Metabolic Pharmaceuticals in Melbourne, with the University of Adelaide leading most human trials.[6][17]
- South Korea: the rabbit osteoarthritis study.[14]
- Germany, Belgium and the US: anti-doping labs showed AOD-9604 does not fool growth hormone tests, characterized seized vials, and developed urine tests for it.[25][24][23]
What users report
Is AOD-9604 legal?
- United States: not FDA-approved. Two compounding nominations were withdrawn; FDA reviewed it anyway, and in December 2024 its advisory committee voted 0 to 12 against allowing it.[1][2][5] It does not appear in any category of FDA’s May 2026 list of substances nominated for compounding under section 503A.[4] FDA lists it among substances with possible immune-reaction risks and serious adverse events of unclear cause.[3]
- “GRAS” claims: in 2012 the company announced a self-affirmed GRAS (generally recognized as safe) determination for food use up to 1 mg a day, made by its own expert panel rather than the FDA.[16]
- Australia: AOD-9604 is a prescription-only (Schedule 4) substance, and possessing it without authority is illegal.[18]
- Sport: WADA bans AOD-9604 at all times as a growth hormone fragment, and it is named again among prohibited peptides on the 2027 list.[19][20]
The Australian sports scandal
AOD-9604 made headlines in 2013 when it was linked to the Essendon Football Club supplements program, and WADA confirmed it was a prohibited substance.[21] The bans that followed in 2016 were for a different peptide, thymosin beta-4 (see our TB-500 profile).[22]
This is general information, not legal advice.
