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 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]
- 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] 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.