Is Sodium phenylbutyrate legal in the United Kingdom?

A chemical chaperone that relieves endoplasmic reticulum stress, and a weak HDAC inhibitor, so it targeted two ageing mechanisms at once. It did not extend mouse lifespan in either sex.

This compound was an attractive candidate because it hits two things on the standard list of ageing hallmarks. Loss of proteostasis is one, and 4-phenylbutyrate is a chemical chaperone that helps misfolded proteins fold and relieves endoplasmic reticulum stress.

Mechanism: Two established activities. As a chemical chaperone it stabilises protein folding intermediates non-specifically and reduces the unfolded protein response, which is the basis of its use in conditions of protein misfolding.

Regulatory history: FDA-approved for urea cycle disorders. Also formed part of a combination product approved for amyotrophic lateral sclerosis that was subsequently withdrawn after its confirmatory trial failed. No ageing indication.

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 Sodium phenylbutyrate 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.