AOD-9604
A 16-amino-acid C-terminal growth hormone fragment studied for lipolytic effects, fat oxidation, and cartilage research without full GH effects.
Molecular Structure
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What is AOD-9604?
AOD-9604 is a 16-amino-acid synthetic peptide based on the C-terminal region (residues 177-191) of human growth hormone, with a tyrosine residue added at the N-terminus to facilitate radiolabeling and improve stability. The compound was developed in the 1990s by researchers at Monash University in Australia, working from earlier observations that the lipolytic activity of growth hormone appeared to reside in a specific C-terminal region of the molecule, distinct from the regions responsible for GH’s growth-promoting and metabolic effects.
AOD-9604 is notable in research for its mechanistic separation of lipolytic activity from full growth hormone receptor signaling. Originally advanced into clinical development by Metabolic Pharmaceuticals as a potential anti-obesity research compound, AOD-9604 progressed through multiple Phase 2 trials before development was discontinued. The compound received Generally Recognized as Safe (GRAS) affirmation from the FDA in 2014 for specific food ingredient applications, though it does not have approval as a pharmaceutical drug in any major jurisdiction.
Mechanism of action
AOD-9604’s mechanisms of action have been investigated across multiple pathways:
- Lipolytic activity: Studies have documented stimulation of lipolysis (triglyceride breakdown in adipose tissue) and inhibition of lipogenesis (new fat formation) in preclinical models, with effects occurring through mechanisms that do not require beta-adrenergic receptor activation.
- Distinct from growth hormone receptor signaling: Although derived from growth hormone, AOD-9604 does not bind the GH receptor with meaningful affinity and does not produce IGF-1 elevation, glucose intolerance, or other systemic GH effects.
- Cartilage tissue effects: Preclinical research has identified potential effects on cartilage tissue, including upregulation of chondrogenic markers and modulation of inflammatory cytokines.
- Effects on lipid metabolism markers: Animal studies have documented changes in fat oxidation rates and adipose tissue gene expression patterns consistent with metabolic shifts toward lipid utilization.
- Receptor mechanism research: The specific receptor or signaling pathway through which AOD-9604 produces its effects remains incompletely characterized, with research suggesting alternative receptor systems beyond the classical GH receptor.
These pathways are characterized primarily in rodent models and limited clinical research.
Research applications
AOD-9604 has been investigated across several research domains, with the most active areas including:
- Obesity and body composition research: Phase 2b clinical research examined effects across multiple doses over 24 weeks. Weight loss in active treatment groups was statistically significant compared to placebo but modest in absolute terms (approximately 2.6 kg at the optimal dose).
- Cartilage and osteoarthritis research: Preclinical and early clinical research has examined effects on cartilage regeneration and osteoarthritis markers, with some studies exploring intra-articular administration in animal models.
- Adipose tissue biology research: The compound is used as a research tool for examining mechanisms of lipolysis and fat metabolism, particularly in research designs where activation of the full GH receptor would be confounding.
- Lipid metabolism research: Studies have examined effects on lipid profiles and adipose tissue gene expression in research models of obesity and metabolic dysfunction.
- Comparative GH research: AOD-9604 has served as a research reference for studying the structure-function relationships within the growth hormone molecule, contributing to broader understanding of which GH activities reside in which structural domains.
This compound is intended for laboratory research use only. It has not been approved for human therapeutic use by any regulatory agency.
Storage & reconstitution
In its lyophilized form, AOD-9604 tolerates ambient temperatures during shipping but should be stored long-term at -20°C, protected from light. Properly stored lyophilized peptide remains stable for 24 months or longer.
Once reconstituted with bacteriostatic water for injection, AOD-9604 solutions should be stored refrigerated at 2-8°C and used within 28 days. Avoid repeated freeze-thaw cycles, which can degrade peptide structure and reduce activity.
Visual inspection should be performed before each use. The reconstituted solution should be clear and colorless. Reject any solution that appears cloudy, discolored, or contains visible particulate matter.
For step-by-step reconstitution calculations, see our reconstitution calculator.
For laboratory research use only. The compound described on this page is intended exclusively for in vitro research and laboratory experimentation by qualified researchers and is not for human or veterinary use. It is not a drug, food, dietary supplement, or cosmetic, and has not been approved by the FDA, Health Canada, EMA, or any other regulatory authority for the diagnosis, treatment, cure, mitigation, or prevention of any disease or medical condition. The information provided on this page is for educational and reference purposes only and does not constitute medical advice. By accessing this content you confirm that you are a qualified researcher purchasing for legitimate laboratory purposes.