Is ISRIB legal in the United Kingdom?

Unlike everything else in this batch, ISRIB is not an approved medicine anywhere and has never been given to a human in a registered trial. It reversed spatial memory deficits in old mice and in mice after traumatic brain injury, and that is the whole case.

This entry belongs in a batch of repurposed prescription drugs as the control case. The other five compounds here are licensed medicines with decades of human safety data being taken off label.

Mechanism: Binds and stabilises the decameric form of eIF2B, the guanine nucleotide exchange factor for eIF2, activating it and so antagonising the translational block imposed by phosphorylated eIF2 alpha. Because the integrated stress response is the convergence point for endoplasmic reticulum stress, viral double-stranded RNA, amino acid deprivation and haem deficiency, inhibiting it downstream affects all four branches at once.

Regulatory history: Not approved for any indication in any country. No registered clinical trial of ISRIB itself exists. A separate eIF2B activator, fosigotifator, is in clinical development for vanishing white matter disease, and two of its trials have been terminated.

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 ISRIB 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.