AOD-9604 is the C-terminal fragment of growth hormone, residues 176–191, with a modification that improves stability. The interesting feature is what it does and what it doesn't: lipolysis without the IGF-1 elevation, glucose interference, or anabolic effects of full-length GH.
Mechanism is beta-3 adrenergic activation in adipocytes. The fragment mobilizes stored fat — especially visceral — and pushes it into the oxidation pathway. There's no insulin sensitivity penalty; in some models there's a modest improvement.
It is the recomposition tool for members with stubborn adipose who don't want or need the GH axis stack. It also has preclinical cartilage benefits, though the lipolytic application is what it's prescribed for.