AOD-9604
GH fragment (lipolytic)
Also AOD9604, AOD 9604, HGH Fragment 176-191, Fragment 176-191, Tyr-hGH 177-191
- Evidence
- CAnimal and cell studies
- FDA status
- Not approvedas of 2026-10-27
- Route
- Injection
- Studies cited
- 0 human2 animal or cell
Sold as a fat-burning piece of growth hormone. It has not worked in people: a company trial of several hundred obese adults found no real weight loss.
Sold for
AOD-9604 is sold as the fat-burning piece of growth hormone, promising lipolysis without the blood-sugar and growth effects of the full hormone.
Studies say
Mouse studies showed increased fat breakdown, but the one sizeable human obesity programme failed to show weight loss and was abandoned, so the fat-loss claim rests on animal data (grade C).
Why grade C. Fat loss is the claimed use. The supporting data are two mouse studies from around 2001 showing lipolytic effects of the growth hormone fragment. A manufacturer-run obesity trial in the mid-2000s found no significant weight loss, and it was never published in full, so no citable human trial exists; the largest published human study is zero. 123
FDA. AOD-9604 is not approved by the FDA for any use and is sold online as a research chemical. The FDA placed it in category 2 of bulk substances nominated for compounding in 2023, citing possible safety risks; its nomination was later withdrawn, and in December 2024 the FDA's Pharmacy Compounding Advisory Committee voted 12-0 against adding it to the list of substances pharmacies may compound.
Written from 11 cited sources. Last refreshed 2026-10-27. Not physician reviewed.
What this means for you
- What people take it for
- Losing body fat.
- Can a US doctor prescribe it?
- No. It is not approved and is sold as a research chemical.
- Properly tested in people?
- Not properly: animal or lab studies, or small uncontrolled human reports. The one large human trial found no real weight loss and was never fully published.
Evidence checklist
- Randomised controlled trial No published human RCTno
- Human study over 100 people No published human study over 100no
- More than one research group Only the manufacturer's own trialsno
- Clinical outcomes, not surrogate markers Phase 2b showed no meaningful weight lossno
- Human safety data beyond case reports Only 'well tolerated' claims, unpublishedno
Drawn from the cited studies below. A dash means the sources give no information.
What it is
AOD-9604 is a synthetic peptide copied from amino acids 177 to 191 at the tail end of human growth hormone, with an extra tyrosine added at the front for stability. The full hormone is 191 amino acids long, so AOD-9604 is a 16-residue fragment of it. The name stands for 'anti-obesity drug' and the number was the developer's code. 45
Metabolic Pharmaceuticals of Melbourne developed it in the late 1990s and early 2000s as an obesity drug, ran clinical trials, and dropped the programme after the results. The peptide then reappeared as an unregulated product sold by research-chemical vendors and used by some anti-ageing clinics. 123
How it works
Growth hormone breaks down fat (lipolysis) and inhibits new fat formation, but it also raises blood glucose and drives tissue growth through IGF-1. The hypothesis behind AOD-9604 was that the lipolytic activity lives in the C-terminal region of the hormone and could be separated from the rest. In obese mice, the fragment increased fat breakdown and reduced weight gain without the glucose effects of full growth hormone. The fragment does not bind the growth hormone receptor the way the full hormone does, and its exact mechanism in fat cells was never fully established. 12
What human research shows
Metabolic Pharmaceuticals ran a series of trials culminating in a six-month phase 2b study of oral AOD-9604 in several hundred obese adults in the mid-2000s. The company reported that the drug did not produce clinically significant weight loss compared with placebo and stopped development. A 2013 review of obesity pharmacotherapy records this as one of the candidates that failed. The full trial data were never published in a peer-reviewed journal. 3
No later human efficacy study has appeared. Published human work since then concerns detection: anti-doping laboratories have characterised how AOD-9604 is metabolised and developed urine tests for it, and confirmed it does not interfere with the standard growth hormone isoform test. 46
| Study | Model | Finding |
|---|---|---|
| Heffernan 2001, Hormone Research | Obese mice, chronic treatment | The C-terminal growth hormone fragment increased fat breakdown and reduced weight gain without the glucose effects of full-length hormone. 1 |
| Heffernan 2001, Int J Obesity | Obese mice | AOD-9604 stimulated lipolysis and inhibited fat formation in a mouse obesity model. 2 |
| Obesity pharmacotherapy review, 2013 | Review including unpublished manufacturer trials | The phase 2b obesity programme did not produce significant weight loss and development stopped. 3 |
| Detection and metabolism study, 2015 | Human serum and urine in vitro | AOD-9604 is quickly broken down; a stable metabolite was identified for anti-doping testing. 4 |
Safety
The manufacturer's trials reported that oral AOD-9604 was well tolerated, which is the one favourable human finding, but the detailed safety data were not published. 3
The FDA's 2023 review placed AOD-9604 in Category 2 for compounding, citing insufficient safety information and concerns about immunogenicity and impurities in peptide products; that decision means licensed pharmacies cannot compound it. Products sold online are not tested for identity or purity, and confiscated vials have been analysed by anti-doping labs. The World Anti-Doping Agency lists AOD-9604 as a prohibited growth hormone fragment. 4789
Questions for your clinician
- Is there any controlled human trial showing AOD-9604 causes fat loss?
- How do I know what is actually in a product sold online?
- Why did the FDA place it in Category 2 for compounding?
Questions people ask
Does AOD-9604 help with fat loss?
In mice, yes. In people, the only sizeable trial, run by the developer, found no significant weight loss versus placebo and the programme was abandoned. No published human study shows fat loss. 123
How does AOD-9604 relate to human growth hormone?
No. It is a 16-amino-acid fragment copied from the end of the 191-amino-acid growth hormone molecule. It does not act through the growth hormone receptor and does not raise IGF-1 the way the full hormone does. 45
Is AOD-9604 FDA-approved or legal to buy?
It is not approved for any use. In 2023 the FDA put it in Category 2 for compounding, so pharmacies cannot legally compound it. It remains sold online labelled for research, outside any regulatory oversight. 79
Citations
- Heffernan 2001, Hormone Research: lipolytic growth hormone fragment in obese mice doi.org
- Heffernan 2001, International Journal of Obesity: AOD9604 in obese mice doi.org
- Current Cardiology Reviews 2013: obesity pharmacotherapy, current perspectives and future directions pubmed.ncbi.nlm.nih.gov
- Drug Testing and Analysis 2015: detection and in vitro metabolism of AOD9604 pubmed.ncbi.nlm.nih.gov
- DailyMed: somatropin label, 191-amino-acid human growth hormone dailymed.nlm.nih.gov
- Drug Testing and Analysis 2013: AOD-9604 does not influence the WADA hGH isoform immunoassay pubmed.ncbi.nlm.nih.gov
- FDA: bulk drug substances that may present significant safety risks in compounding fda.gov
- WADA: 2026 Prohibited List wada-ama.org
- FDA: 503A bulk drug substances category list (2023 update) fda.gov
- FDA Drugs@FDA: tesamorelin (Egrifta) approval record accessdata.fda.gov
- Falutz 2007, NEJM: metabolic effects of tesamorelin in patients with HIV pubmed.ncbi.nlm.nih.gov