Is TUDCA legal in the United Kingdom?

Twenty obese adults, four weeks: hepatic and muscle insulin sensitivity rose about 30 percent on a clamp, while adipose tissue insulin sensitivity and the endoplasmic reticulum stress markers the drug was meant to fix did not change. In ALS the phase 3 trial of TUDCA combined with sodium phenylbutyrate missed its endpoint and the approved product was voluntarily withdrawn from the market.

TUDCA is the taurine conjugate of ursodeoxycholic acid, which has its own entry on this site. The two are not interchangeable, and supplement marketing routinely treats them as though they were.

Mechanism: A hydrophilic bile acid that acts as a chemical chaperone, stabilising protein folding and reducing endoplasmic reticulum stress, and separately raising the threshold for mitochondrial permeability transition so that less cytochrome c is released and less apoptosis occurs. Conjugation with taurine increases water solubility and changes how the molecule is handled in the enterohepatic circulation relative to unconjugated ursodeoxycholic acid, which is why the two are studied separately.

Regulatory history: Not approved as a single agent. A fixed combination of sodium phenylbutyrate and taurursodiol was FDA-approved for ALS and then voluntarily withdrawn by its sponsor after the phase 3 PHOENIX trial showed no change on the primary functional endpoint. TUDCA on its own is sold as a dietary supplement.

Licenses medicines for the UK market. A compound without a marketing authorisation is an unlicensed medicine, which can only lawfully be supplied for human use through a prescriber under the specials scheme, not sold as a research product.

The classification above is the The Longevity Archive reading of Medicines and Healthcare products Regulatory Agency listings for TUDCA 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.