AOD-9604
Modified GH-fragment peptide
A modified fragment of human growth hormone studied in lipolysis research.
Overview
AOD-9604 is a synthetic, stabilized analog of the C-terminal lipolytic region (residues 176-191) of human growth hormone, developed in the 1990s at Monash University. It adds an N-terminal tyrosine to the native fragment and retains the intramolecular disulfide bridge between the two cysteine residues.
At a glance
What AOD-9604 does
AOD-9604 is a modified fragment of the C-terminus of human growth hormone (residues 176-191 with an added tyrosine) engineered to isolate GH's fat-metabolizing activity from its growth-promoting effects. Its core action in research is stimulating lipolysis, the breakdown of stored triglycerides in adipocytes, and inhibiting lipogenesis, the formation of new fat. Mechanistically, preclinical work attributes this to upregulation and increased sensitivity of the beta-3 adrenergic receptor, the dominant lipolytic receptor in fat tissue, which drives cAMP-mediated activation of hormone-sensitive lipase. Critically, unlike full-length GH, AOD-9604 does not raise IGF-1, does not bind the GH receptor in a growth-signaling way, and in studies did not impair glucose tolerance or insulin sensitivity, which is the whole point of the fragment's design.
The evidence base is mixed across the preclinical-to-clinical gap. In obese rodents, AOD-9604 reduced body-weight gain and increased fat oxidation. In humans, a 12-week randomized placebo-controlled trial of roughly 300 obese adults on 1 mg/day oral dosing reported modest weight loss versus placebo, and the compound showed a clean safety and tolerability profile with no genotoxicity signal. However, subsequent Phase IIb obesity trials failed to meet their primary weight-loss endpoint, and pharmaceutical development was discontinued around 2007. So the honest read is: a well-characterized lipolytic mechanism, a strong safety record, but human weight-loss efficacy that was inconsistent and ultimately unconvincing to its developers.
Effects reported in research
- Stimulates lipolysis (breakdown of stored triglycerides) in adipocytes, the core studied action.
- Inhibits lipogenesis, reducing the conversion of non-fat food energy into new body fat (preclinical).
- Upregulates and sensitizes the beta-3 adrenergic receptor to drive cAMP-mediated fat breakdown (mechanistic/animal data).
- Increases fat oxidation and reduced body-weight gain in obese mouse models.
- Does NOT elevate IGF-1 or activate GH growth signaling, unlike full-length growth hormone.
- Did not impair glucose tolerance or insulin sensitivity in studies, distinguishing it from GH's diabetogenic effect.
- Produced modest weight loss (~2.6 kg vs ~0.8 kg placebo) in one 12-week human trial, but later Phase IIb trials missed their primary endpoint.
- Showed a favorable human safety/tolerability profile with no genotoxicity detected.
Effects listed reflect findings reported in the research literature — many in animal or in-vitro models. Listing an effect is not a claim of efficacy or a therapeutic indication in humans.
Mechanism of action
AOD-9604 corresponds to the C-terminal fragment of GH that carries the hormone's lipolytic (fat-metabolizing) activity while lacking the regions responsible for GH's growth-promoting and insulin-antagonizing effects. In preclinical models it has been reported to stimulate lipolysis and inhibit lipogenesis. It does not act as a full growth hormone and reportedly does not raise IGF-1 or affect blood glucose in the manner of intact GH.
Mechanistic description reflects published research-literature understanding. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
What it's studied for
Research contexts in which AOD-9604 appears in the literature. Listing a research area is not a claim of efficacy or a therapeutic indication.
Key characteristics
- A peptide analog of the GH C-terminal fragment 176-191, with an added N-terminal tyrosine
- Retains a disulfide bridge between its two cysteine residues, intended to stabilize the loop conformation
- Designed to isolate GH's lipolytic activity from its growth and glucose effects
- Human clinical trials for obesity did not demonstrate significant weight-loss efficacy versus placebo
- Not an approved drug; used as a research compound
Reported research dosing reference only
Educational reference, not dosing guidance. The figures below summarize amounts reported in published research and research-community protocols, provided for educational and research context only. They are not medical advice, not a recommendation, and not instructions for human use. AOD-9604 is a research compound.
Widely-referenced research summaries and extrapolations from early human trials cite roughly 300 mcg/day as a common reference figure, referenced to a ~70 kg subject. These are figures reported for research context only and are not dosing guidance for humans.
- Commonly-referenced research protocol: ~300 mcg/day reconstituted, reported administered once daily
- Reported reference range in research summaries: ~300-500 mcg/day (referenced to ~70 kg)
Human trials did not confirm meaningful clinical fat-loss efficacy; reference figures are for research framing only. Not dosing guidance for humans.
How it compares
Unlike full-length GH or GH secretagogues, AOD-9604 targets only the lipolytic C-terminal region; unlike the raw HGH Fragment 176-191, it carries an extra N-terminal tyrosine intended to improve stability.
Commonly studied alongside
Compounds frequently researched together with AOD-9604 in the literature. Cross-referenced for research context — not a usage or combination recommendation.
Handling & Stability
Lyophilized peptides are stored cold, protected from light, and reconstituted only at the time of intended in-vitro work.
- Avoid repeated freeze-thaw cycles
- Verify supplier lot and Certificate of Analysis
- Follow institutional lab-safety protocols
Analytical & COA Concepts
Reputable research suppliers publish a third-party Certificate of Analysis per batch. Key analytical concepts referenced in COAs include:
Category Context
AOD-9604 sits in the Metabolic & Mitochondrial area of the PeptiDex library.
- Entry type: Research compound reference
- Browse the full library →
- Glossary of terms →
Where researchers source AOD-9604
For researchers studying AOD-9604, third-party suppliers such as Practically Natty Peptides offer research-grade material with third-party Certificates of Analysis and US-based shipping.
View research-supplier listing →
Outbound link to a third-party research supplier. Inclusion does not constitute endorsement; all editorial content is developed independently.
Frequently asked questions
What is AOD-9604 and what class of compound is it?
AOD-9604 is a synthetic 16-amino-acid peptide corresponding to the C-terminal region (residues 176-191) of human growth hormone, modified with an added N-terminal tyrosine and a disulfide bridge between its two cysteine residues. It is studied as a lipolytic (fat-metabolism) peptide that appears to isolate the fat-mobilizing activity of GH. It is a research peptide, not an approved therapeutic in most jurisdictions.
How does AOD-9604 differ from unmodified HGH Fragment 176-191?
AOD-9604 is a stabilized analog of HGH Fragment 176-191: it adds a tyrosine residue at the N-terminus of the native fragment. This modification was engineered in preclinical work to improve metabolic stability and lipolytic activity relative to the raw fragment. Both are studied for fat metabolism, but AOD-9604 is the more characterized, stabilized version.
Does AOD-9604 raise IGF-1 or affect blood glucose in research models?
In preclinical models, AOD-9604 was reported to stimulate lipolysis and inhibit lipogenesis without the growth-promoting or diabetogenic effects associated with full-length growth hormone. Studies indicate it does not meaningfully elevate IGF-1 or disturb glucose handling in the models examined. These findings are from research settings and are not clinical guarantees.
Is AOD-9604 an approved drug?
AOD-9604 has been investigated in human trials (including for obesity, where it did not meet primary efficacy endpoints) and has held GRAS-type designations in some contexts, but it is not an approved pharmaceutical drug for fat loss. It is handled as a research compound. Any use outside a controlled research setting is not supported by an approval.
How should AOD-9604 be stored and reconstituted for research?
AOD-9604 is supplied as a lyophilized powder and is typically reconstituted with bacteriostatic or sterile water for laboratory handling. Lyophilized peptide is generally stored refrigerated (2-8 C) or frozen for longer terms; reconstituted solution is kept refrigerated and used within a limited window. A COA with HPLC purity (commonly >=98%) and mass-spec identity confirmation is standard.
Answers are educational summaries of research-literature context and do not constitute medical advice. See the Research Library, COA guide, and Storage & Handling guide for more.