AOD-9604
Also known as: Fragment 176-191
Modified C-terminal fragment of the growth hormone peptide. Studied in lipid-metabolism research.
Mechanism of action
AOD-9604 is a synthetic peptide made of the last 15 amino acids of human growth hormone (positions 177 to 191) with an extra tyrosine added at the start. Its exact target is not known: in cell tests it did not bind the growth hormone receptor or drive cell growth as growth hormone does, yet in obese rodents it raised markers of fat breakdown (lipolysis) and lowered markers of fat synthesis (Heffernan et al., Int J Obes 2001). It is often described as activating beta-3 adrenergic receptors, but the mouse study usually cited concluded it does not act directly on that receptor: it raised the amount of beta-3 receptor in fat tissue, and its longer-term effects were absent in mice lacking the receptor, while its short-term effect on energy use remained (Heffernan et al., Endocrinology 2001).