Is GDF15 legal in the United States?

A stress cytokine that acts on the hindbrain to cause nausea, aversion and weight loss. The drug that worked in people blocks it: ponsegromab produced 1.2 to 2.8 kg of weight gain versus placebo in 187 people with cancer cachexia. A GDF15 agonist given to 126 adults with obesity produced minimal weight loss.

GDF15 is a member of the TGF-beta superfamily that circulates as a roughly 25 kDa dimer and rises in response to almost any cellular stress: mitochondrial dysfunction, tissue injury, inflammation, chemotherapy, pregnancy and metformin. Its receptor, GFRAL, was identified by several groups at once in 2017 and is expressed almost exclusively in the area postrema and nucleus of the solitary tract, the brainstem region that produces nausea and food aversion.

Mechanism: Established in mice and confirmed at the receptor level in human tissue expression: GDF15 binds GFRAL, which requires the co-receptor RET to signal, in neurons of the area postrema and nucleus of the solitary tract. Activation reduces food intake and produces conditioned taste aversion; deleting GFRAL abolishes the weight loss effect of GDF15 in mice.

Regulatory history: Not FDA-approved. No GDF15 agonist or antagonist has a Drugs@FDA record as of 11 September 2026. Ponsegromab, an antibody that blocks GDF15, is in phase 2/3 for cancer cachexia; the GDF15 agonist MBL949 produced minimal weight loss in a 2025 phase 2.

Approves prescription drugs by indication and polices unapproved products, including peptides sold online. Compounding pharmacies may prepare some compounds under a prescription when the FDA places them on a permitted bulk-substances category.

The classification above is the The Longevity Archive reading of U.S. Food and Drug Administration listings for GDF15 at the reviewed date, not a legal opinion. Rules change, and importing, prescribing and possessing a compound can each be treated differently. Check the regulator directly before acting on anything here.