AOD-9604

Educational overview

Not FDA-approved. FDA cites limited safety information plus potential immunogenicity, impurity, and serious-adverse-event concerns.

AOD-9604 is a synthetic peptide of 16 amino acids that copies the C-terminal region of human growth hormone (residues 177 to 191) with an added tyrosine at one end. It was designed in Australia at Monash University to retain the fat-metabolism actions attributed to that fragment of growth hormone while leaving out the growth-promoting and insulin-antagonising effects of the whole hormone. Because it does not act on the growth hormone receptor in the usual way and does not raise IGF-1, it is often described as a lipolytic fragment rather than a growth hormone secretagogue. The name comes from the developer's compound code; it is also sold as hGH fragment 176-191.

Animal studies from the Monash group and the developer, Metabolic Pharmaceuticals, reported reduced weight gain and increased adipose lipolysis in obese Zucker rats and mice without loss of insulin sensitivity. Human evidence comes from an obesity development programme in the early 2000s that the sponsor stopped after a phase 2b trial failed to show meaningful weight loss; the aggregated safety data were later published outside the major indexed journals. Independent work since then has focused on anti-doping detection methods and a rabbit osteoarthritis model. The FDA's 2024 review found no, or only limited, safety-related information and noted serious adverse events that may be associated with the peptide, although causality was unclear.

AOD-9604 is not approved as a medicine by the FDA, the EMA, the TGA or any other regulator. In the United States it was nominated for the list of bulk substances that can be used in compounding under section 503A; the nominations were withdrawn, the FDA nevertheless reviewed it at the Pharmacy Compounding Advisory Committee meeting of December 2024, and the agency's published table lists it among substances that may present significant safety risks, citing immunogenicity for certain routes, peptide-related impurities and difficulties with characterising the active ingredient. Products sold online as research chemicals are unapproved drugs when marketed for human use. The World Anti-Doping Agency names AOD-9604 as an example of a prohibited growth hormone fragment under section S2.

There is no approved product label for AOD-9604, so no regulator-reviewed storage, reconstitution or in-use period exists. Material on the market is usually a lyophilised powder whose identity and purity depend entirely on the supplier; the FDA's 2024 briefing document noted inconsistent CAS numbers, structures and certificates of analysis among vendors. Peptides of this kind are generally supplied with a request to keep the dry powder cold and protected from light, and reconstituted solutions have no established beyond-use time. A dose log or inventory record therefore carries the burden of traceability: supplier, batch, reconstitution date, resulting concentration and storage conditions are the only fields that later allow a product-quality question to be investigated.

Category

Investigational metabolic peptide

Routes represented

Subcutaneous (SubQ)

Storage context

Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.