AOD-9604

What it is

AOD-9604 is a synthetic peptide fragment derived from human growth hormone. It was developed by Metabolic Pharmaceuticals in Australia as part of an effort to separate the fat-metabolism effects attributed to the C-terminal region of growth hormone from the broader growth-promoting actions of full-length recombinant human growth hormone^{[3 ,8 ]}. The molecule is sometimes described in older commercial and research literature as Tyr-hGH(177-191), reflecting the 15-amino-acid human growth hormone fragment plus an added tyrosine residue^{[3 ,8 ]}.

The original biological rationale was based on preclinical work suggesting that the C-terminal fragment of growth hormone could influence lipid metabolism without activating the classical growth hormone receptor effects that increase IGF-1^{[3 ,7 ]}. In obese mouse models, AOD-9604 was reported to reduce weight gain and alter markers of fat oxidation and lipolysis, while beta3-adrenergic receptor knockout models suggested that some effects depended on intact beta3-adrenergic signaling^{[7 ]}. FDA’s 2024 PCAC briefing concluded that the molecular targets and mechanisms underlying AOD-9604’s pharmacological effects remain unknown^{[3 ]}.

Human development focused mainly on obesity and metabolic endpoints. A 2013 safety and tolerability paper summarized six randomized, placebo-controlled human studies conducted from 2001 to 2006, with intravenous and oral exposure in approximately 900 adult participants, most of whom were clinically obese^{[8 ]}. Those studies are not the same as FDA-reviewed approval trials, and AOD-9604 never became an FDA-approved obesity drug.

When described in clinical or grey-market use, AOD-9604 has been administered intravenously, orally, subcutaneously, and topically depending on the study or commercial claim^{[3 ,8 ]}. This page describes reported routes and regulatory history only. It does not provide dosing guidance or endorse use.

Regulatory status

AOD-9604 is not FDA-approved for obesity, osteoarthritis, cartilage repair, body composition, athletic performance, or any other indication in the United States. FDA’s AOD-9604 PCAC briefing states that there is no applicable USP or National Formulary monograph for AOD-9604 free base or AOD-9604 acetate, and that neither is a component of an FDA-approved drug^{[3 ]}.

503A pharmacy compounding

For 503A pharmacy compounding, FDA states that state-licensed pharmacists and physicians may compound with a bulk drug substance only when the substance complies with an applicable USP/NF monograph, is a component of an FDA-approved drug product when no monograph exists, or appears on FDA’s 503A bulks list when neither of those pathways applies^{[4 ]}. AOD-9604 does not meet those conditions based on FDA’s AOD-specific briefing and the current 503A list reviewed for this draft^{[1 ,3 –4 ]}.

503B outsourcing facilities

For 503B outsourcing facilities, FDA states that a bulk drug substance generally must appear on the 503B bulks list or the compounded drug must appear on FDA’s drug shortage list at the time of compounding, distribution, and dispensing^{[5 ]}. No FDA-compliant 503B pathway for routine AOD-9604 compounding was identified in the FDA sources reviewed for this draft^{[5 ]}.

Nomination history and safety-risk listing

Regulatory history is unusually important for this peptide. FDA received nominations for AOD-9604-related bulk drug substances for possible inclusion on the 503A bulks list; those nominations were later withdrawn, and FDA evaluated AOD-9604 free base and AOD-9604 acetate on its own initiative^{[3 ]}. FDA’s April 22, 2026 safety-risk page lists AOD-9604 among bulk substances previously in Category 2 whose nominations were withdrawn and states that compounded products containing AOD-9604 may pose immunogenicity and peptide-impurity concerns, with only limited safety-related information^{[2 ]}.

Controlled-substance status

AOD-9604 is not listed in the federal controlled-substance schedules in 21 CFR Part 1308 as reviewed on May 7, 2026^{[6 ]}. Anti-doping status is a separate issue from DEA scheduling or FDA approval; this page does not provide sports-eligibility advice.

Research summary

The strongest preclinical metabolic evidence comes from obese rodent studies. Heffernan and colleagues reported that chronic treatment with AOD-9604 altered weight-gain and lipid-metabolism measures in obese mice, and that the effect was not reproduced in beta3-adrenergic receptor knockout mice^{[7 ]}. FDA’s review summarized additional rodent studies and noted reduced body-weight gain, increased fat oxidation, and increased plasma glycerol in obese mice treated with AOD-9604, while also emphasizing that the relevant human mechanism remains uncertain^{[3 ]}.

Human metabolic studies — Stier 2013 and FDA review

Human metabolic efficacy is not established. The 2013 Stier, Vos, and Kenley paper summarized six randomized, double-blind, placebo-controlled trials and focused primarily on safety markers such as IGF-1, glucose tolerance, insulin resistance, anti-AOD-9604 antibodies, and adverse events^{[8 ]}. Public summaries of the development program and FDA’s PCAC review indicate that AOD-9604 did not become an approved obesity drug, and FDA evaluated the substance for obesity in the compounding context rather than recognizing it as an approved therapy^{[3 ,8 ]}.

The 2013 tolerability paper reported no consistent increases in IGF-1, no detected anti-AOD-9604 antibodies in tested samples, and no serious adverse event judged related to AOD-9604 by the authors^{[8 ]}. FDA’s later review was more cautious. FDA noted limited clinical safety information, lack of pharmacokinetic and bioavailability information across routes, insufficient long-term safety information for obesity, and possible safety concerns including immunogenicity risk and adverse events reported in human studies, with causality not always assessable^{[2 –3 ]}.

Osteoarthritis preclinical work

Osteoarthritis and cartilage claims are much less developed than obesity claims. Kwon and Park studied intra-articular AOD-9604, with and without hyaluronic acid, in a rabbit osteoarthritis model and reported changes in cartilage and inflammatory markers^{[9 ]}. That is preclinical animal evidence; it does not establish efficacy, dosing, or safety for human osteoarthritis.

Anti-doping detection and grey-market product analysis

Several publications are primarily analytical or anti-doping oriented rather than therapeutic. Cox and colleagues described detection and in vitro metabolism of AOD-9604 for drug-testing purposes^{[10 ]}. Vanhee and colleagues reported identification of AOD-9604 in seized unknown pharmaceutical preparations, illustrating grey-market quality and identification concerns^{[11 ]}. Orlovius and colleagues found that AOD-9604 did not influence a WADA hGH isoform immunoassay, a finding relevant to testing methodology rather than clinical efficacy^{[12 ]}.

Overall, AOD-9604 has preclinical metabolic data, limited human tolerability summaries, and no FDA-approved therapeutic indication. Claims that it reliably causes clinically meaningful human fat loss, builds muscle, repairs human cartilage, or improves athletic performance are not established by published peer-reviewed clinical trials as of May 7, 2026.

Public discourse

Gary Wittert, MD, Professor of Medicine and obesity researcher, discussed AOD-9604 during the Australian football doping controversy and stated that human evidence did not support claims of fat loss or muscle building^{[13 ]}.

In the same interview, Wittert cautioned that available safety data did not answer long-term use questions, especially for repeated injection routes outside the studied context^{[13 ]}.

No additional podcast, YouTube, or public-figure sources were included because the search found mostly marketing pages, anonymous forum discussion, and unverified claims.

Public discourse reflects the views of the speakers cited and does not represent medical advice or the editorial position of ProPeptideGuide.

Side effects and safety

Human safety data are limited and come largely from early obesity-development studies summarized by the sponsor-linked 2013 paper and by FDA’s later PCAC review^{[3 ,8 ]}. Reported adverse events in those studies included headache, fatigue, dizziness, gastrointestinal symptoms, euphoria, chest tightness, diarrhea, and other nonspecific events; FDA noted that some serious adverse events were reported but that causality could not always be assessed from the available information^{[3 ]}.

Compounding-specific concerns

FDA identified several theoretical and practical concerns for compounded AOD-9604 products: immunogenicity risk, peptide aggregation, peptide-related impurities, API characterization challenges, route-specific uncertainty, and lack of adequate human pharmacokinetic or pharmacodynamic information^{[2 –3 ]}. These issues are especially relevant because compounded or grey-market peptide products may differ in salt form, purity, storage, concentration, and formulation^{[2 –3 ]}.

Long-term safety unknown

Long-term safety data are not adequate for chronic obesity or body-composition use. FDA specifically noted insufficient information to support patient safety for long-term use in obesity and no information to assess pharmacokinetic or pharmacodynamic effects in humans^{[3 ]}. The limited human studies do not establish safety for repeated unsupervised injection, transdermal products, athlete use, or combinations with other growth hormone axis agents.

No established contraindication list, drug-interaction profile, pregnancy safety profile, or long-term surveillance dataset exists for AOD-9604 comparable to an FDA-approved prescribing label. The absence of an FDA-approved label is itself an important safety limitation because there is no FDA-reviewed product standard, indication, dosing framework, or risk-management language for clinicians and patients to rely on^{[3 –5 ]}.

Available through

AOD-9604 is not currently available through FDA-compliant prescription or compounding channels in the United States as of 2026-05-07^{[1 –5 ]}. It is not FDA-approved, is not on the 503A bulks list, was withdrawn from the 503A nomination category process, and was not identified on the 503B bulks list or as a shortage-list-driven 503B pathway^{[1 –5 ]}.

ProPeptideGuide does not link to or endorse grey-market vendors, “research chemical” sellers, online peptide shops, or clinics advertising AOD-9604 for fat loss, body composition, cartilage repair, or athletic performance.