AOD-9604

AOD-9604 contains only amino acids 176–191 of the 191-amino-acid human GH molecule—the C-terminal region associated with lipolytic activity. Full-length GH activates the GH receptor (GHR) and produces IGF-1 elevation, insulin resistance, tissue growth, and sodium retention. AOD-9604 acts through beta-3 adrenergic receptors on adipocytes for lipolysis rather than through the GHR, and does not stimulate IGF-1 production. Clinical studies confirm it does not affect blood glucose, IGF-1, or bone growth at therapeutic doses—making it metabolically 'cleaner' than GH for fat-targeted research applications.

AOD-9604 received regulatory approval in Australia as a listed therapeutic goods ingredient for osteoarthritis treatment, based on preclinical evidence of chondroprotective effects. It is approved as 'AOD-9604' specifically for this application. The obesity-targeted Phase 2b clinical trials (Monash University/Metabolic Pharmaceuticals) completed successfully in terms of fat loss but effect sizes were not deemed sufficient for Phase 3 FDA submission. The compound is not FDA-approved and is not approved as a pharmaceutical in the United States.

Several Phase 1 and Phase 2 trials were conducted in Australia and globally between 2001–2008. A 24-week Phase 2b trial enrolling over 500 obese subjects showed statistically significant reductions in body weight (~3–4 kg greater than placebo) and preferential visceral fat loss versus subcutaneous fat. The results confirmed the mechanism and established safety, but the modest absolute effect size was insufficient to support a New Drug Application. The trials established an excellent safety profile with no IGF-1 elevation, no blood glucose effects, and adverse events comparable to placebo.

AOD-9604 received 'Generally Recognized as Safe' (GRAS) status determination from a US FDA GRAS notification (GRN 000237) for use as a food ingredient at specified levels. This designation was based on its amino acid composition and the extensive safety data from clinical trials. However, the GRAS designation as a food ingredient is categorically different from FDA drug approval and does not authorize its use as a therapeutic drug in the United States. The distinction is important: food ingredient safety standards and pharmaceutical efficacy/safety standards are separate regulatory frameworks.

The chondroprotective effects of AOD-9604 appear to be independent of its lipolytic mechanism. In vitro studies show AOD-9604 promotes chondrocyte proteoglycan synthesis (type II collagen and aggrecan production) and reduces MMP (matrix metalloproteinase) activity that degrades cartilage. In sheep osteoarthritis models, intra-articular injection significantly reduced modified Mankin scores (cartilage degradation assessment) and preserved cartilage thickness versus controls. The specific receptor mediating these effects has not been definitively identified—it may involve IGF-1 receptor cross-reactivity despite the absence of systemic IGF-1 elevation.

AOD-9604's selective fat loss without GH side effects results from its receptor selectivity. Full-length GH produces growth, glucose elevation, IGF-1 increase, and sodium retention through GH receptor (GHR) activation. AOD-9604 lacks the GHR binding domain of GH (located in the N-terminal region) while retaining the C-terminal fragment responsible for activating beta-3 adrenergic receptors on adipocytes. Beta-3 adrenergic activation stimulates adipocyte lipolysis (fat breakdown and release) and thermogenesis specifically in adipose tissue without affecting glucose metabolism, IGF-1 production, or growth plates. This mechanism explains its clean safety profile in clinical trials.

AOD-9604 for osteoarthritis has progressed beyond preclinical stages. The compound is listed as an approved therapeutic goods ingredient in Australia for OA applications, and its chondroprotective properties were demonstrated in multiple animal models. Intra-articular injection studies in sheep showed cartilage preservation over 6–12 months. Phase 2 human clinical trials for knee OA have been conducted in Australia under the sponsorship of companies utilizing the compound's GRAS and regulatory status. As of 2026, this application has not advanced to large-scale Phase 3 registration trials in major markets (US/EU), limiting regulatory approval outside of Australian listed medicine status.

AOD-9604 can be used alongside GH secretagogues (sermorelin, ipamorelin) without pharmacological conflict since they act through entirely different mechanisms. Combining AOD-9604's direct lipolytic effects with GH secretagogue-mediated GH elevation could theoretically produce additive fat loss—the secretagogue drives GH pulses (with systemic anabolic effects) while AOD-9604 specifically amplifies adipocyte fat mobilization. This combination is used in some research protocols, though no published studies have specifically assessed the combination's pharmacodynamics. AOD-9604 is also sometimes combined with BPC-157 in joint-health research protocols, given their overlapping potential in tissue repair.