AOD-9604: The Fat-Loss Peptide That Failed Its Own Trial
AOD-9604 is a growth-hormone fragment with strong fat-loss data in animals — but its pivotal human obesity trial failed, and it was never approved as a medicine.
By Research Rats Editorial TeamReviewed by Research Rats Editorial Team
Evidence profile
Assessed 2026-07-02Strong rodent fat-loss data and reassuring short-term human tolerability, but the pivotal 24-week human weight-loss trial failed its primary endpoint; it is unapproved and WADA-prohibited.
A modified growth-hormone C-terminal fragment proposed to be lipolytic without raising IGF-1; the mechanism is plausible but not clearly established.
Strong, fairly consistent fat-loss data in mice and rats.
Human trials exist (pooled short-term safety plus a pivotal 24-week weight-loss RCT), but the pivotal efficacy trial missed its primary endpoint and the obesity programme was abandoned.
The endpoint that matters for fat loss came back negative in controlled human data.
Short-term human tolerability looked clean (no IGF-1 rise, no glucose problems), but trials lasted weeks to months and long-term/special-population safety is unknown.
Reached Phase 2 then was discontinued; no active development.
The informative negative trial gives moderate confidence that meaningful human fat loss is not supported.
Never approved as a medicine; WADA-prohibited. Its Category 2 nomination was later withdrawn, so it is NOT currently in the active Category 2 table — not a clearance, and FDA still publishes the identified concerns. In a related proceeding FDA continued its evaluation on its own initiative and in December 2024 PROPOSED against 503A Bulks List inclusion, with the advisory committee voting 0-12 against; that is a proposal and a recommendation, NOT a final rule. The 'FDA GRAS' label refers only to food-ingredient safety, not therapeutic approval.
Bars show the state of evidence, not desirability. A strong rating on any axis does not mean a compound is safe, effective, or recommended. Human evidence is often limited. Not medical advice.
What to know before reading further
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Evidence context
A growth-hormone fragment with strong fat-loss data in mice and rats and reassuring short-term human safety across pooled trials — but its pivotal 24-week human weight-loss trial failed its primary endpoint, and the obesity programme was abandoned.
Safety snapshot
Short-term human tolerability looked clean (no IGF-1 rise, no glucose problems), but the trials lasted weeks to months and long-term and special-population safety are unknown.
Regulatory & legality
Never approved as a medicine; the circulating 'FDA GRAS' label refers only to food-ingredient safety, not efficacy or therapeutic approval. WADA-prohibited. Its Category 2 bulk-substance nomination was later withdrawn, so it is not currently in the active Category 2 table — but a withdrawal is not approval or clearance and the FDA still publishes the concerns it identified. In a related proceeding, FDA proposed against 503A Bulks List inclusion in December 2024 and the advisory committee voted 0-12 against inclusion; that is a proposal and a committee recommendation, not a final rule.
Where claims can exceed the evidence
The part that matters for fat loss — does it work in humans — came back negative; claims of meaningful human fat loss are not supported by controlled data.
This article does not provide dosing, protocol, administration, sourcing, stack, or self-experimentation guidance, or personalised medical advice. It is educational and non-prescriptive — the evidence profile describes the state of research, not an individual decision.
Overview
AOD-9604 is one of the more interesting cautionary tales in the peptide world. On paper it sounds ideal: a fragment of human growth hormone (hGH) that switches on fat burning without the blood-sugar and tissue-growth baggage of the full hormone. In rodents, that promise held up remarkably well. In humans, it did not.
The honest summary is this: AOD-9604 has strong preclinical evidence for lipolysis (fat breakdown) in obese mice and rats [1][2], and good human safety data from six pooled placebo-controlled trials [5]. But the pivotal 24-week human weight-loss trial failed its primary endpoint, and the company developing it abandoned the obesity programme in 2007 [12]. It has never been approved as a medicine anywhere [10].
So this is not a story of a banned-but-effective drug. It is a story of a mechanistically elegant compound whose animal results simply did not translate into meaningful weight loss in people. That distinction matters enormously if you are considering it.
Disclaimer. For educational and research purposes only. Not medical advice. We do not sell peptides or compounds.
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