Is FGF17 legal in the United States?

The factor identified when young cerebrospinal fluid was infused into aged mouse brains. In humans it is known for a different reason: FGF17 mutations cause congenital hypogonadotropic hypogonadism.

A 2022 Nature paper took a different route into the young-blood question by asking about cerebrospinal fluid rather than plasma, on the reasoning that CSF is the immediate environment of brain cells. Infusing young CSF directly into aged mouse brains improved memory function.

Mechanism: In mice, young cerebrospinal fluid boosts oligodendrocyte progenitor proliferation and differentiation in the aged hippocampus through serum response factor, a transcription factor driving actin cytoskeleton rearrangement whose expression falls with age in hippocampal progenitors. FGF17 was identified by screening CSF for activators of that pathway, and FGF17 infusion alone induced progenitor proliferation and long-term memory consolidation in aged mice while FGF17 blockade impaired cognition in young mice.

Regulatory history: Not approved and never administered to a human. No registered trial of FGF17 for any indication could be located.

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 FGF17 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.