AOD-9604 is a synthetic peptide made of the C-terminal fragment of human growth hormone (hGH), residues 177 to 191, with an extra tyrosine added at the N-terminus.[2] The sequence is YLRIVQCRSVEGSCGF,...
AOD-9604 is a synthetic peptide made of the C-terminal fragment of human growth hormone (hGH), residues 177 to 191, with an extra tyrosine added at the N-terminus.[2] The sequence is YLRIVQCRSVEGSCGF, closed into a loop by a disulfide bond between its two cysteines; PubChem lists the formula C78H123N23O23S2, a molecular weight of 1815.1 g/mol and CAS 221231-10-3.[1] Pepitiva supplies AOD-9604 as a lyophilized powder (5 mg vials, ≥98% purity) for in vitro and preclinical research.
Origin of the name
AOD stands for "anti-obesity drug". The peptide came out of work on the lipolytic domain of hGH, and the company Metabolic developed it for the potential treatment of obesity, with Phase IIa trials under way by 2002.[7][9] We found no peer-reviewed report of those obesity trials in PubMed, so human efficacy data remain largely unpublished.
AOD-9604 and HGH Fragment 176-191
AOD-9604 is often sold as "HGH Fragment 176-191", but the native hGH 176-191 sequence starts with phenylalanine rather than tyrosine. See HGH Fragment 176-191 for the comparison.
For research use only. Not for human consumption.
Quality & Storage
≥98% purity. Lyophilized powder. Storage: -20°C. For research purposes only.
Mechanism of Action
Lipid metabolism without growth hormone receptor binding
In preclinical work, AOD9604 reproduced part of the fat-metabolism activity of hGH while behaving differently from the full hormone at the receptor level:
No hGH receptor binding: AOD9604 did not compete for the hGH receptor and did not stimulate proliferation of cells transfected with it, unlike hGH.[3]
Fat oxidation and lipolysis: in obese mice treated for 14 days, both hGH and AOD9604 reduced body weight gain, increased fat oxidation and raised plasma glycerol, an index of lipolysis. Unlike hGH, AOD9604 did not induce hyperglycemia or reduce insulin secretion.[3]
Beta-3 adrenergic receptors: AOD9604 raised the repressed beta-3 adrenergic receptor RNA of obese mice to lean levels, but its chronic effects were lost in beta-3 receptor knockout mice; an acute dose still increased energy expenditure and fat oxidation in those knockouts. The authors concluded the lipolytic action is not mediated directly through the beta-3 receptor.[4]
Insulin sensitivity: in obese Zucker rats given AOD9604 orally for 19 days, weight gain was more than 50% lower than in controls, and euglycemic clamps showed no adverse effect on insulin sensitivity.[5]
Enzymes: the parent 177-191 domain (AOD9401) stimulated hormone-sensitive lipase and inhibited acetyl-CoA carboxylase in adipocytes, and reduced average adipocyte diameter from 110 to 80 µm in Zucker rats.[6]
Structure
NMR analysis of the 15-residue cyclic parent peptide (hGH 177-191, without the added tyrosine) showed two type I beta-turns within the disulfide loop and structural similarity to the same region of intact hGH. The peptide stimulated lipolysis and inhibited lipogenesis in rodent, porcine and human adipose tissue in vitro.[7]
Research Applications
Other preclinical findings
Cartilage (2015): in a rabbit knee osteoarthritis model, intra-articular AOD9604 improved cartilage scores and shortened lameness compared with saline, and the combination with hyaluronic acid outperformed either alone.[8]
Analytical and anti-doping research
AOD9604 is banned by the World Anti-Doping Agency. A validated urine method detects it down to 50 pg/mL, and its most stable serum metabolite is the fragment CRSVEGSCG.[2]
AOD9604 does not interfere with the WADA hGH isoform immunoassay.[13]
The peptide has been identified in unlabeled preparations seized by Belgian authorities and in confiscated vials in the USA.[2][12]
Laboratory research applications
Adipose tissue assays: lipolysis, lipogenesis and fat oxidation, with full-length hGH as comparator.
Adrenergic signaling: beta-3 adrenergic receptor expression in obese models.
AOD-9604 is not approved as a drug, and a 2026 review notes that rigorous human safety data for unapproved peptides of this kind are scarce.[10] The FDA has stated that compounded drugs containing AOD-9604 may pose a significant risk of immunogenicity for certain routes of administration and that it identified no, or only limited, safety-related information; the substance appears on FDA's list of nominations later withdrawn by the nominator.[11] This product is sold for laboratory research only.
Storage & Handling Guidelines
Proper storage and handling are essential to maintain peptide integrity and ensure reliable research results. All Pepitiva Biolabs peptides are supplied as lyophilized (freeze-dried) powder, which provides excellent long-term stability when stored correctly. Store lyophilized peptides at -20°C for long-term storage or 2-8°C for short-term use. Once reconstituted, peptide solutions should be stored at 2-8°C and used within the timeframe specified in the product documentation. Always use sterile bacteriostatic water for reconstitution and handle peptides in a clean laboratory environment to prevent contamination. Avoid repeated freeze-thaw cycles, as thermal stress can cause peptide degradation and loss of biological activity.
Quality Control & Certification
This product is manufactured under strict quality control protocols and has been verified through comprehensive analytical testing. Each batch undergoes reverse-phase HPLC analysis for purity determination and electrospray ionization mass spectrometry (ESI-MS) for molecular identity confirmation. A detailed Certificate of Analysis (COA) is available for download, documenting purity percentage, molecular weight verification, appearance, and recommended storage conditions. Pepitiva Biolabs maintains batch-level traceability from synthesis through delivery, ensuring complete transparency and quality assurance for your research.
Frequently Asked Questions
What is AOD-9604?
A synthetic 16-amino-acid peptide (YLRIVQCRSVEGSCGF) made of human growth hormone residues 177 to 191 plus an N-terminal tyrosine. It was developed as a potential anti-obesity drug.
What is the difference between AOD-9604 and HGH Fragment 176-191?
Native hGH 176-191 begins with phenylalanine (1799.1 g/mol); AOD-9604 replaces it with tyrosine (1815.1 g/mol, CAS 221231-10-3). Suppliers often use the names interchangeably. See HGH Fragment 176-191.
Does AOD-9604 act like growth hormone?
Only partly. In obese mice it increased fat oxidation and lipolysis like hGH, but it did not bind the hGH receptor, did not stimulate cell proliferation and did not cause hyperglycemia.
Is AOD-9604 FDA approved?
No. AOD-9604 is not an approved drug. The FDA has listed safety concerns for compounded AOD-9604, including possible immunogenicity and limited safety information.
Is AOD-9604 banned in sport?
Yes. AOD9604 is on the World Anti-Doping Agency prohibited list, and validated urine tests can detect it and its metabolites.
How should AOD-9604 be stored?
Keep the lyophilized powder at −20 °C, protected from light and moisture.
Is this product approved for human use?
No. This product is intended exclusively for in vitro scientific research and laboratory use. It is not approved for human or veterinary use, not intended for diagnostic or therapeutic purposes, and should not be administered to humans or animals under any circumstances.
How do I reconstitute this peptide?
Add sterile bacteriostatic water slowly to the vial, directing the stream against the glass wall rather than directly onto the lyophilized powder. Gently swirl the vial until the powder is fully dissolved — do not shake vigorously. The recommended reconstitution volume depends on your desired concentration. Refer to the product documentation for specific guidance.
Can I get a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis is included with every order and is also available for download from the product page. The COA documents HPLC purity, mass spectrometry identity confirmation, batch number, production date, and storage recommendations.
Cox HD, Smeal SJ, Hughes CM, et al. Detection and in vitro metabolism of AOD9604. Drug Test Anal. 2015;7(1):31-8. PubMed
Heffernan MA, Thorburn AW, Fam B, et al. Increase of fat oxidation and weight loss in obese mice caused by chronic treatment with human growth hormone or a modified C-terminal fragment. Int J Obes Relat Metab Disord. 2001;25(10):1442-9. PubMed
Heffernan M, Summers RJ, Thorburn A, et al. 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):5182-9. PubMed
Ng FM, Sun J, Sharma L, et al. Metabolic studies of a synthetic lipolytic domain (AOD9604) of human growth hormone. Horm Res. 2000;53(6):274-8. PubMed
Ng FM, Jiang WJ, Gianello R, et al. Molecular and cellular actions of a structural domain of human growth hormone (AOD9401) on lipid metabolism in Zucker fatty rats. J Mol Endocrinol. 2000;25(3):287-98. PubMed
Ogru E, Wilson JC, Heffernan M, et al. The conformational and biological analysis of a cyclic anti-obesity peptide from the C-terminal domain of human growth hormone. J Pept Res. 2000;56(6):388-97. PubMed
Kwon DR, Park GY. Effect of Intra-articular Injection of AOD9604 with or without Hyaluronic Acid in Rabbit Osteoarthritis Model. Ann Clin Lab Sci. 2015;45(4):426-32. PubMed
Wilding J. AOD-9604 Metabolic. Curr Opin Investig Drugs. 2004;5(4):436-40. PubMed
Mendias CL, Awan TM. Safety and Efficacy of Approved and Unapproved Peptide Therapies for Musculoskeletal Injuries and Athletic Performance. Sports Med. 2026;56(8):1921-1935. PubMed
U.S. Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks (AOD-9604, under nominated but withdrawn). Page last updated April 22, 2026. Accessed October 8, 2026. Source
Vanhee C, Moens G, Deconinck E, et al. Identification and characterization of peptide drugs in unknown pharmaceutical preparations seized by the Belgian authorities: case report on AOD9604. Drug Test Anal. 2014;6(9):964-8. PubMed
Orlovius AK, Thomas A, Schänzer W, et al. AOD-9604 does not influence the WADA hGH isoform immunoassay. Drug Test Anal. 2013;5(11-12):850-2. PubMed
Sources are peer-reviewed publications indexed in PubMed and trial registrations on ClinicalTrials.gov. Each citation was checked against its PubMed record.
For research use only. Not for human consumption.
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