Is AOD-9604 an approved drug?

No. AOD-9604 is an investigational peptide supplied strictly for laboratory research use only. It is not an approved medicine and is not intended to diagnose, treat, cure or prevent any disease, nor for human or veterinary use. Clinical development as an anti-obesity drug was discontinued in 2007 after trials showed insufficient efficacy.

What is AOD-9604 derived from?

It is a synthetic 16-amino-acid peptide corresponding to the C-terminal lipolytic region of human growth hormone (residues 177-191) with an added N-terminal tyrosine. The two cysteine residues form an intramolecular disulfide bridge, so it is a cyclic rather than a simple linear peptide.

What did studies report about its mechanism?

Researchers reported that AOD-9604 retains the lipolytic and anti-lipogenic activity of growth hormone without raising IGF-1 or affecting glucose metabolism. In rodent models the lipolytic effect was not mediated directly through the beta-3 adrenergic receptor, though the peptide raised the suppressed beta-3 receptor RNA in obese mice toward lean-animal levels.

What did the human trials show?

A Phase 2b trial in obese adults reported a modest, dose-related weight reduction (about 2 kg greater than placebo at the 1 mg oral dose at 12 weeks) with a safety profile described as indistinguishable from placebo. The effect was judged insufficient for drug registration and a later confirmatory trial did not demonstrate adequate efficacy.

What is the evidence grade?

Grade C-B. The animal data are reasonably consistent and there is a large human safety dataset, but human efficacy rests on a single sub-registration Phase 2b trial, and the compound has never been approved as a medicine.

AOD-9604 Dosage, Half-Life & Research

AOD-9604 is a synthetic 16-amino-acid peptide corresponding to the C-terminal lipolytic region of human growth hormone (residues 177-191) with an added N-terminal tyrosine.¹ It was developed by Metabolic Pharmaceuticals (Australia) as an investigational anti-obesity agent intended to reproduce the fat-metabolising actions of growth hormone without growth-hormone’s effects on IGF-1 or glucose.²It is not an approved drug. A Phase 2b obesity trial reported only a modest weight-loss signal, a subsequent longer trial failed to show sufficient efficacy, and clinical development for obesity was discontinued in 2007.³ Most positive efficacy data come from rodent models; human efficacy has been inconsistent.¹ This material is sold for laboratory research use only and is not for human or veterinary use.

Structure

Sequence & identity

Tyr-Leu-Arg-Ile-Val-Gln-Cys-Arg-Ser-Val-Glu-Gly-Ser-Cys-Gly-Phe (disulfide Cys7–Cys14) · C₇₈H₁₂₃N₂₃O₂₃S₂ · 1815.1 g/mol

Identity verified against PubChem CID 71300630; InChIKey GVIYUKXRXPXMQM-BPXGDYAESA-N, CAS 221231-10-3.⁴ The two cysteines form an intramolecular disulfide bridge, giving a cyclic (non-linear) peptide.

What the research shows

Mechanisms studied

Researchers reported that AOD-9604 retains the lipolytic and anti-lipogenic activity of the growth-hormone C-terminus while producing no measurable change in IGF-1 or carbohydrate metabolism.¹² In obese mice and in β3-adrenergic-receptor knock-out mice, Heffernan and colleagues observed that the lipolytic effect was not mediated directly through the β3-adrenergic receptor, although both growth hormone and AOD-9604 raised the suppressed β3-receptor RNA in obese mice toward lean-animal levels, which the authors suggested could secondarily enhance lipolytic sensitivity.¹ In rodent adipose models, investigators reported increased fat oxidation and reduced fat accumulation without signs of glucose intolerance.¹ Animal pharmacokinetic work (intravenous dosing in pigs) reported a very short plasma half-life of roughly 3 minutes with a Tmax near 2 minutes, attributed to rapid enzymatic degradation; no human pharmacokinetic study has been characterised.⁵

Reported in studies

Dosing in the research literature

The figures below summarise regimens as reported in published research — they are not recommendations or directions for use.

Source / model	Regimen reported	Notes
Stier et al. 2013, J Endocrinol Metab (human safety program, 893 subjects across six trials, 2001-2006)²	As reported in studies: intravenous 25-400 µg/kg body weight (20-minute infusion); oral capsules/tablets 0.25-54 mg.	Doses reported across six randomized, placebo-controlled clinical studies in (in all but one study) obese adults. AOD-9604 had no detectable effect on serum IGF-1 and no significant change in oral glucose tolerance; tolerability was described as indistinguishable from placebo. Reported here as study parameters only — not directions for use.
Phase 2b obesity trial (approximately 300 obese subjects), Metabolic Pharmaceuticals, reported in contemporaneous trial reports and summarised in Stier et al. 2013²³	As reported in studies: oral once daily at 1, 5, 10, 20 or 30 mg (with placebo) for 12 weeks.	At the 1 mg dose, studies reported mean weight loss of about 2.8 kg at 12 weeks versus about 0.8 kg on placebo. The effect was judged insufficient for drug registration and a later, longer trial did not confirm efficacy; development was halted. Study parameter only.

Research use only. Peptigo products are sold to qualified researchers for laboratory use. This information summarises published research for reference and is not medical advice, a dosing recommendation, or directions for human or animal use.

Reported in studies

Effects observed in research

In rodent studies, researchers observed reduced body weight and adipose mass, increased fat oxidation, and restoration of suppressed β3-adrenergic-receptor expression toward lean-animal levels.¹ In humans, a Phase 2b trial reported a modest, dose-related reduction in body weight at 12 weeks (about 2 kg greater than placebo at the 1 mg oral dose).²³ Across the clinical program, investigators reported no effect on serum IGF-1, fasting glucose, insulin, HbA1c, cortisol or thyroid hormones, and no anti-AOD-9604 antibodies were detected.² The human weight-loss effect was not large enough to support registration as an obesity drug, and a longer confirmatory trial failed; this is an honest limit of the evidence rather than a demonstrated clinical benefit.³

Honest assessment

Strength of evidence

Grade C-B

Grade C-B. The animal evidence is relatively consistent (multiple rodent studies reporting lipolysis and reduced fat mass without IGF-1 or glucose effects),¹ and there is a sizeable human dataset for safety (893 subjects across six trials, with a tolerability profile described as indistinguishable from placebo).² However, human efficacy rests on a single Phase 2b trial whose best result was a roughly 2 kg placebo-adjusted weight loss that was deemed insufficient for registration, and a later trial failed to confirm benefit, leading the developer to discontinue the obesity program in 2007.³ Because the efficacy signal comes from one sub-registration human trial against otherwise preclinical data, the grade is held at the C-B boundary. AOD-9604 has never been approved as a medicine and should be regarded as an investigational compound with promising preclinical data but unproven clinical efficacy.

Handling

Reconstitution & storage

Reconstitute with bacteriostatic water for laboratory handling. Store lyophilised material frozen and reconstituted material refrigerated. Use Peptigo’s reconstitution calculator and storage cheat sheet for working figures.

References

Heffernan M, Summers RJ, Thorburn A, Ogru E, Gianello R, Jiang WJ, Ng FM. 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. 2001;142(12):5182-5189. https://pubmed.ncbi.nlm.nih.gov/11713213/
Stier H, Vos E, Kenley D. Safety and Tolerability of the Hexadecapeptide AOD9604 in Humans. J Endocrinol Metab. 2013;3(1-2):7-15. https://doi.org/10.4021/jem157w
AOD9604 — development history and discontinuation of the obesity program in 2007 following insufficient Phase 2b and later-trial efficacy (Metabolic Pharmaceuticals). Wikipedia, citing primary trial reports: https://en.wikipedia.org/wiki/AOD9604
PubChem Compound Summary for CID 71300630 (AOD-9604; Tyr-hGH 177-191): MolecularFormula C78H123N23O23S2, MolecularWeight 1815.1, InChIKey GVIYUKXRXPXMQM-BPXGDYAESA-N, CAS 221231-10-3. U.S. National Library of Medicine. https://pubchem.ncbi.nlm.nih.gov/compound/71300630
More MI, Kenley D. Safety and Metabolism of AOD9604, a Novel Nutraceutical Ingredient for Improved Metabolic Health. J Endocrinol Metab. 2014;4(3):64-77. (Animal PK: intravenous 400 µg/kg in pigs, T1/2 approximately 3 min, Tmax approximately 2 min.) https://jofem.org/index.php/jofem/article/view/213

Written by the Peptigo Research Team · scientifically reviewed by Peter, Peptigo Research Team · Last reviewed June 2026. We cite primary literature and flag where evidence is limited. Our sourcing & RUO policy →