AOD‑9604 is a modified C‑terminal fragment of human growth hormone that retains the lipolytic (fat‑reducing) domain without the growth‑promoting effects[1]. It binds to adipose tissue and triggers breakdown of stored fat while blocking new fat storage (re‑esterification) in adipocytes[4]. At the molecular level, chronic AOD‑9604 administration upregulates β3‑adrenergic receptors in fat tissue, reversing obesity‑related suppression of these fat‑burning receptors[9]. Unlike full‑length hGH, AOD‑9604 does not meaningfully elevate IGF‑1 levels or worsen glucose tolerance, making its tolerability indistinguishable from placebo in human trials[2][3].