AOD-9604.
AOD-9604 ("Advanced Obesity Drug 9604") is a synthetic 16-amino-acid peptide corresponding to the C-terminal lipolytic region of human growth hormone (hGH), residues 177–191, with an added tyrosine at the N-terminus.
AOD-9604 ("Advanced Obesity Drug 9604") is a synthetic 16-amino-acid peptide corresponding to the C-terminal lipolytic region of human growth hormone (hGH), residues 177–191, with an added tyrosine at the N-terminus. AOD-9604 is research / preclinical, and PepCue grades its published evidence D tier (41/100). This is a research reference, not medical or dosing advice.
What it is
AOD-9604 ("Advanced Obesity Drug 9604") is a synthetic 16-amino-acid peptide corresponding to the C-terminal lipolytic region of human growth hormone (hGH), residues 177–191, with an added tyrosine at the N-terminus. It was engineered in the 1990s by researchers at Monash University and developed by the Australian biotech Metabolic Pharmaceuticals as an orally-investigated anti-obesity agent. The design goal was to isolate hGH's fat-mobilizing activity while leaving out the growth-promoting, IGF-1-stimulating actions of the full hormone.
How it works
In rodent models, AOD-9604 reproduces the lipolytic (fat-breakdown) and fat-oxidation–promoting effects of full-length growth hormone without binding the GH receptor and without raising IGF-1. Mechanistic work in obese and beta-3-adrenergic-receptor knockout mice indicated its effect on fat metabolism is associated with modulation of beta-3 adrenergic receptor activity and increased lipolysis and fat oxidation rather than classic GH-receptor signaling. Because it does not engage the GH receptor, it was hypothesized to avoid the insulin-resistance and tissue-growth liabilities of GH itself. Importantly, the cleanly receptor-independent, IGF-1-sparing profile is best characterized in animal and in-vitro work, not firmly established in humans.
Mechanism pathways
Acting directly on fat tissue to increase fat breakdown or reduce its blood supply.
This pathway groups compounds that act on adipose tissue itself rather than on appetite. Lipolysis is the enzymatic breakdown of stored triglycerides into free fatty acids and glycerol, executed by adipose triglyceride lipase and hormone-sensitive lipase inside the fat cell. It is normally triggered by catecholamines acting on beta-adrenergic receptors, which raise cyclic AMP and activate protein kinase A. Growth hormone also stimulates lipolysis, but it does so as part of a package that includes growth promotion and a rise in insulin resistance. Several compounds here derive from the observation that growth hormone's fat-mobilising activity appears to reside in the carboxy-terminal region of the molecule, separate from the domain that binds and activates the growth hormone receptor. Isolating that region was intended to produce fat breakdown without raising IGF-1 or impairing glucose handling. Mechanistic work in rodents linked the effect to beta-3 adrenergic receptor activity rather than to growth hormone receptor signalling. One member of this group is the plain fragment; another is a modified analog with an added amino-terminal residue and considerably more development history behind it. A second, entirely different approach targets the blood supply instead of the fat cell. A homing sequence binds prohibitin, a protein unusually abundant on the endothelial cells lining blood vessels within white adipose tissue, and delivers a pro-apoptotic sequence that kills those cells once internalised. The intent is to shrink fat depots by starving them of perfusion. This is a vascular-targeting strategy borrowed from oncology and is conceptually unrelated to lipolysis. A third approach targets an enzyme, nicotinamide N-methyltransferase, which is highly expressed in adipose tissue and consumes both nicotinamide and methyl groups from S-adenosylmethionine. Inhibiting it is proposed to spare nicotinamide for NAD+ regeneration and to shift adipocytes toward energy expenditure rather than storage. Clinical relevance across this group is weak. The growth hormone fragment analog was carried into human obesity trials and did not produce clinically meaningful weight loss beyond placebo, and it was not approved as a medicine. The plain fragment has essentially no human evidence of its own and borrows its reputation from that analog. The vascular-targeting compound raised kidney toxicity concerns in primate work and did not progress. The enzyme inhibitor's downstream logic is plausible but largely inferred from animal and cell studies. None of these are approved for any use.
The evidence
Preclinical evidence is the strongest part of the AOD-9604 record: chronic dosing reduced body-weight gain and increased fat oxidation in obese mice (Heffernan et al., Int J Obes, 2001; PMID 11673763). It progressed into human obesity trials in the early-mid 2000s; a 12-week randomized study reported only a modest separation from placebo (on the order of ~1–2 kg), and development was halted around 2007 after a larger ~24-week trial failed to show meaningful weight-loss efficacy, particularly once diet and exercise were standardized. No peer-reviewed pivotal trial demonstrates clinically useful weight loss, and there is no robust human evidence for the commonly marketed claims around cartilage, joint, or tendon repair: those rest on limited preclinical/early work. In short, the human data are negative-to-thin for obesity and largely absent for other indications.
The evidence, in brief
A synthetic fragment of the C-terminus of hGH studied for fat-metabolizing (lipolytic) effects. Despite early interest, later human obesity trials (including a Phase IIb) failed to show clinically meaningful weight loss versus placebo, and it was never approved.
- Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormoneHorm Res, 2000 (PMID 11146367)
Evidence maturity
An evidence-only reading: approval status, human vs preclinical data, mechanism and safety. Popularity never raises it. Research file #005
Some human signal atop preclinical work; gaps remain.
Some early human evidence exists but isn't definitive.
Claim receipts
Popular claims about AOD-9604, checked against the state of the evidence. The verdict describes evidence maturity, never an invented study result.
Human obesity trials failed to show meaningful weight loss and the development program was halted.
It was designed to avoid GH-receptor activation and looked clean short-term, but the fat-loss half of the claim did not survive human testing.
Joint and cartilage claims rest on limited preclinical and early-stage work.
It was nominated as a bulk compounding substance and flagged as raising significant safety questions, which is not clearance.
Safety profile
Across the obesity trials, AOD-9604 was generally reported as well tolerated with a clean short-term safety signal, which is part of why it was later nominated for compounding review; however, these data come from time-limited studies and do not establish long-term safety. There is no established safety profile for chronic use, for injectable research-grade ("gray market") product, or for the unindicated cosmetic, joint, and anti-aging uses now marketed online. Purity, identity, and contamination of non-pharmaceutical material are real concerns, underscored by published forensic identification of illicit AOD9604 preparations (Drug Testing and Analysis, 2014; PMID 24976118). No dosing or administration guidance is provided here.
Compound notes
- AOD-9604 (“anti-obesity drug 9604”) is a modified fragment of the C-terminal region (176-191) of human growth hormone.
- It was engineered to target fat metabolism (lipolysis) without the growth-promoting, IGF-1-raising effects of full GH.
- Human obesity trials were largely disappointing (it did not produce significant weight loss), and it is not approved as a weight-loss drug.
- Not FDA-approved for weight loss; research-only.
- Marketed claims outrun the underwhelming human trial results.
Regulatory status
AOD-9604 is not approved by the FDA (or any major regulator) for any therapeutic use; its obesity development program was discontinued, and it remains investigational/research-use-only. The FDA has evaluated it among nominated bulk drug substances for pharmacy compounding under section 503A and has flagged peptide candidates of this type as raising significant safety questions; it is also prohibited in sport and tested for by anti-doping authorities under the WADA framework.
Sold research-use-only; human evidence is limited or preclinical.
By the numbers
- 01Synthetic fragment of human growth hormone (residues 177–191) plus an N-terminal tyrosine; 16 amino acids
- 02Developed by Metabolic Pharmaceuticals (Australia) from Monash University research as an anti-obesity candidate
- 03Designed to mobilize fat without GH-receptor binding or IGF-1 elevation; best shown in animal models, not confirmed in humans
- 04Obesity drug development was halted around 2007 after later trials failed to show meaningful weight loss
- 05Not FDA-approved for any use; investigational/research-use-only and reviewed as a nominated compounding bulk substance
- 06Prohibited in sport and tested for under WADA anti-doping rules
AOD-9604: research formats
Choose the format you are researching to see route-specific notes.
GH fragment; requires acetic acid for reconstitution. Similar format to IGF-1 LR3.
AOD-9604 (HGH fragment 176–191) is a C-terminal fragment of GH. Like other basic/aggregation-prone fragments, it requires initial reconstitution in 0.6% acetic acid before diluting with BAC water. Sold as a 2–5 mg vial.
Sources
Every factual claim above resolves to a real, published source.
- Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragmentInternational Journal of Obesity and Related Metabolic Disorders, 2001, PMID: 11673763
- Identification and characterization of peptide drugs in unknown pharmaceutical preparations seized by the Belgian authorities: case report on AOD9604Drug Testing and Analysis, 2014, PMID: 24976118
- PubMed search: AOD9604 (all indexed literature)PubMed/NCBI, ~22 records as of 2026
- Certain Bulk Drug Substances for Use in Compounding That May Present Significant Safety Risks / 503A nominated substancesU.S. FDA, Human Drug Compounding
Cite this page
PepCue. “AOD-9604: the evidence.” PepCue, reviewed June 1, 2026. https://www.pepcue.app/p/aod-9604.
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