AOD-9604

AOD-9604 is a synthetic peptide representing a modified fragment of human growth hormone (hGH), specifically amino acids 177-191 of the hGH molecule with an added tyrosine at the N-terminus. Developed at Monash University in Melbourne, Australia, it was designed to isolate the fat-reducing properties of growth hormone without its growth-promoting, insulin-resistant, or IGF-1-elevating effects. This targeted approach aimed to create a safer anti-obesity agent compared to full growth hormone therapy.

Preclinical research on AOD-9604 showed promising results in animal models of obesity. Studies in obese mice and rats demonstrated significant reductions in body fat without changes in food intake or lean body mass. The peptide appeared to stimulate lipolysis (fat breakdown) and inhibit lipogenesis (fat formation) through mechanisms involving beta-3 adrenergic receptors and modulation of fat cell metabolism. Importantly, it did not increase IGF-1 levels or impair glucose tolerance in these models.

However, the translation from animal models to human clinical outcomes was disappointing. A phase 2b clinical trial involving over 500 obese participants showed no statistically significant difference in weight loss between AOD-9604 and placebo over 24 weeks. Despite the negative clinical trial results, Metabolic Pharmaceuticals (the developing company) continued to explore other applications, and the peptide eventually found a different path as a component in cartilage repair research.

In 2007, the TGA (Therapeutic Goods Administration) in Australia approved AOD-9604 as a food substance with GRAS (Generally Recognized as Safe) status. More recently, AOD-9604 has been studied for its potential in cartilage and bone repair, with some research suggesting it may promote chondrocyte (cartilage cell) proliferation. Despite the inconclusive weight loss data, AOD-9604 remains popular in the peptide community based on its mechanism of action and safety profile.