Is Beta-2 Microglobulin legal in the United States?

A blood protein that rises with age and impairs neurogenesis and memory when injected into young mice. In people it is a long-established clinical analyte and is associated with worse cognition; nobody has tried lowering it for ageing.

Beta-2 microglobulin is the light chain of MHC class I molecules and is present in everyone's blood. A 2015 Nature Medicine paper identified it as a circulating pro-ageing factor: B2M is elevated in the blood of ageing humans and mice and in the hippocampus of aged mice and young heterochronic parabionts.

Mechanism: In mice, systemic or intrahippocampal B2M impairs hippocampal-dependent cognition and neurogenesis, effects partly mitigated by reducing cell-surface MHC class I. The 2023 molecular work identifies B2M as an endogenous NMDA receptor antagonist acting through the GluN1-S2 loop, with competitive peptides restoring receptor-dependent synaptic function.

Regulatory history: No B2M-lowering therapy is approved for ageing or cognition and none is in a registered trial for those uses. B2M is measured clinically as a laboratory analyte in renal and haematological medicine.

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 Beta-2 Microglobulin 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.