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A growth-hormone fragment that reached phase 2 for obesity two decades ago and stopped there.
Also known as: AOD9604 · hGH fragment 176-191 related
Part of the Metabolic & GLP-1 peptides cluster
Overview
AOD-9604 is a synthetic 16-residue peptide based on the C-terminal region of human growth hormone (residues 177–191 with an added N-terminal tyrosine), developed by Metabolic Pharmaceuticals as an obesity drug and in phase 2a trials by 2002 (Wilding, Current Opinion in Investigational Drugs 2004). It was never approved, has no registered trials today, and appears in anti-doping detection literature as a non-approved substance.
Source & context
Biological / chemical source: Synthetic fragment related to human growth hormone C-terminus
Primary research or clinical context: Investigational obesity drug in the early 2000s (phase 2a); development did not lead to approval; sold unapproved as a research chemical
What AOD-9604 is
AOD-9604 (“anti-obesity drug 9604”) is a synthetic peptide corresponding to residues 177–191 of human growth hormone with a tyrosine added at the N-terminus — 16 residues in all, including the disulfide loop at the C-terminal end of the hormone. The design idea was to isolate the region of growth hormone thought to drive fat metabolism while discarding the parts responsible for growth and insulin-antagonising effects. It was developed by the Australian company Metabolic Pharmaceuticals; by February 2002 phase 2a trials for obesity were under way (Wilding, Current Opinion in Investigational Drugs 2004).
The fragment hypothesis
Growth hormone is a 191-residue protein with many actions, including lipolysis, and the C-terminal region had been implicated in the metabolic effects. A fragment that retained lipolytic signalling without somatotropic activity would be an attractive obesity drug and would avoid the glucose-raising and growth effects of the whole hormone. That is the educational value of AOD-9604: it is a textbook example of sequence fragmentation as a drug-design strategy, and of how a promising fragment can fail to translate. The mechanism in humans was never confirmed in a published pivotal trial.
Clinical development and what happened to it
AOD-9604 was listed among obesity drugs in clinical development in the mid-2000s (Halford, Current Opinion in Investigational Drugs 2006) and tracked in contemporary clinical-trial gateways (Bayés et al., Methods and Findings in Experimental and Clinical Pharmacology 2003–2005). The sources reviewed do not report positive pivotal results, and no approval followed in any jurisdiction. As of September 2026 no study of AOD-9604 is registered on ClinicalTrials.gov, and the compound survives in the literature mainly as an anti-doping analyte and as a name in the grey market. The honest summary is that a phase 2 programme two decades ago did not produce a medicine.
| Period | Context | Source |
|---|---|---|
| 2002–2006 | Obesity drug in phase 2a; listed among drugs in development | Wilding, 2004; Halford, 2006 |
| 2013–2014 | Anti-doping: detection methods; no effect on the WADA hGH isoform assay | Orlovius et al., 2013; Thevis et al., 2014 |
| 2026 | Named among unapproved peptides in sports-medicine reviews | Mendias & Awan, 2026; Rahman et al., 2026 |
| Registered trials | None | — |
Anti-doping context
Because AOD-9604 derives from growth hormone, anti-doping laboratories examined whether it would confound growth-hormone testing; it does not influence the WADA hGH isoform immunoassay (Orlovius et al., Drug Testing and Analysis 2013). Detection approaches for it and other non-approved peptides in doping control were subsequently described (Thevis and Schänzer, Journal of Pharmaceutical and Biomedical Analysis 2014; Thevis et al., Expert Review of Proteomics 2014). Its presence in this literature reflects use in sport as an unapproved substance, not evidence of efficacy.
Pharmacokinetics
No human pharmacokinetic values for AOD-9604 are reported in the abstracts reviewed. The phase 2a-era papers are development summaries rather than pharmacology reports, and later publications concern detection. A defined half-life or bioavailability cannot be stated from the available sources.
Regulatory status as of September 2026
AOD-9604 is not an approved medicine in the United States, Canada, the European Union or Australia, where it was developed. It is sold online as a “research peptide” for fat loss; such products are unlicensed and of unverified content, and marketing them for human use is illegal in those jurisdictions. Recent sports-medicine reviews list it among grey-market peptides without an evidence base for the uses claimed (Mendias and Awan, Sports Medicine 2026).
AOD-9604 vs the growth-hormone secretagogues
AOD-9604 is often grouped with sermorelin, CJC-1295, ipamorelin and MK-677, but it belongs to a different idea. The secretagogues make the pituitary release more growth hormone; AOD-9604 is a piece of growth hormone meant to act directly on fat metabolism without raising growth hormone or IGF-1 at all. That is also why it does not interfere with growth-hormone doping tests. The growth-hormone secretagogues guide covers the other family.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.
- Molecular form
- Tyr-hGH(177–191): the C-terminal 15 residues of human growth hormone with an N-terminal tyrosine, 16 residues; contains the hGH disulfide between Cys182 and Cys189
- Species
- Not established by this molecular identity audit
- Termini (N / C)
- Not specified / Not specified
Average reference mass
Reference policy updated: 2026-10-05
- PubChem molecular record · 2026-10-01
- Molecular formula
- C78H123N23O23S2
- Average reference mass
- ≈ 1,815.1
- Backbone
- Tyr-hGH(177–191): the C-terminal 15 residues of human growth hormone with an N-terminal tyrosine, 16 residues; contains the hGH disulfide between Cys182 and Cys189
- Status
- Not approved anywhere; no trials registered on ClinicalTrials.gov (snapshot September 2026)
- PubChem CID: 71300630
- CAS RN: 221231-10-3
- UNII: 7UP768IP4M
Chemistry values: curated profile, PubChem · fetched 2026-10-01.
AOD-9604 — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Tyr-hGH(177–191): the C-terminal 15 residues of human growth hormone with an N-terminal tyrosine, 16 residues; contains the hGH disulfide between Cys182 and Cys189Average reference mass: 1,815.1 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- EditorialProfile content reviewed and updated by the editorial team.
FAQ about AOD-9604
What is AOD-9604?+
AOD-9604 is a synthetic 16-residue peptide based on the C-terminal region of human growth hormone (residues 177–191 with an added N-terminal tyrosine), developed by Metabolic Pharmaceuticals as an obesity drug and in phase 2a trials by 2002 (Wilding, Current Opinion in Investigational Drugs 2004). It was never approved, has no registered trials today, and appears in anti-doping detection literature as a non-approved substance.
What Canadian product status is recorded for AOD-9604?+
Canadian product status for AOD-9604 has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the typical length of AOD-9604?+
AOD-9604 is commonly described as approximately 16 amino acids (Research peptide).
What is AOD-9604?+
A 16-residue synthetic peptide based on the C-terminal 177–191 region of human growth hormone, developed as an obesity drug in the early 2000s. It was never approved.
Does AOD-9604 work for fat loss?+
It reached phase 2a trials for obesity by 2002; the sources reviewed report no positive pivotal trial and no approval followed. There are no registered trials today.
Is AOD-9604 approved?+
No, in no jurisdiction.
Does AOD-9604 raise growth hormone?+
No. It is a fragment of the hormone, not a secretagogue, and it does not affect the WADA growth-hormone isoform test (Orlovius et al., 2013).
Is AOD-9604 banned in sport?+
It appears in anti-doping detection literature as a non-approved substance; athletes should check the current WADA list.
What are AOD-9604's side effects?+
No published controlled safety data are available in the sources reviewed.
Further reading
- Hormone axisGH Secretagogue Peptides Explained: CJC-1295, Ipamorelin, GHRPsEducational overview of growth hormone secretagogue peptides—GHRH analogs vs GHRPs, DAC vs no DAC, receptors, and research context.
- FoundationsWhat Are Research Peptides? A Clear Educational GuideLearn what “research peptides” means, how they differ from approved peptide drugs, quality markers (COA, purity), and how to study them responsibly.
- SafetyPeptide Safety and Risks: A Balanced Educational OverviewAn objective, balanced overview of what research does and does not establish about peptide risks—unknowns, purity and contamination concerns, and why unapproved compounds carry uncertainty. Not reassurance and not medical advice.
- Not a peptideIs MK-677 (Ibutamoren) a Peptide? No — It Is an Oral Small-Molecule Ghrelin Mimetic. What the Trials ShowedMK-677 (ibutamoren) is sold next to peptides and stacked with them, but it is a small synthetic molecule that activates the ghrelin receptor by mouth. This guide explains what it is, how it differs from GHRH and GHRP peptides, what its clinical trials showed — including the safety signal that stopped one — and its regulatory status.
Related peptides
References & further reading
- 1.Wilding (2004). AOD-9604 Metabolic. Curr Opin Investig Drugs
- 2.Kwon et al. (2015). Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model. Ann Clin Lab Sci
- 3.Cox et al. (2015). Detection and in vitro metabolism of AOD9604. Drug Test Anal
- 4.Orlovius et al. (2013). AOD-9604 does not influence the WADA hGH isoform immunoassay. Drug Test Anal
- 5.Ng et al. (2000). Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Horm Res
- 6.Heffernan et al. (2001). The effects of human GH and its lipolytic fragment (AOD9604) on lipid metabolism following chronic treatment in obese mice and beta(3)-AR knock-out mice. Endocrinology
- 7.Vanhee et al. (2014). Identification and characterization of peptide drugs in unknown pharmaceutical preparations seized by the Belgian authorities: case report on AOD9604. Drug Test Anal
- 8.Halford (2006). Obesity drugs in clinical development. Current Opinion in Investigational Drugs
- 9.Thevis & Schänzer (2014). Analytical approaches for the detection of emerging therapeutics and non-approved drugs in human doping controls. Journal of Pharmaceutical and Biomedical Analysis
- 10.Thevis et al. (2014). Detecting peptidic drugs, drug candidates and analogs in sports doping: current status and future directions. Expert Review of Proteomics
- 11.Mendias & Awan (2026). Safety and efficacy of approved and unapproved peptide therapies for musculoskeletal injuries and athletic performance. Sports Medicine
- 12.PubChem — AOD-9604, CID 71300630