Is (R/S)-1,3-Butanediol legal in the United Kingdom?

In people, it raises blood ketones for a few hours. In 9 cyclists, it gave 5 of them moderate to severe gut problems and did not make them faster. In mice, it gave the NIA lifespan program's most shaky result. Females gained 2 percent in typical lifespan, but only when one lab was counted. Males gained 9 percent, but only by a test that counts early deaths more. The mice ate it as 10 percent of their food by weight.

1,3-butanediol is a small alcohol. The liver turns it into beta-hydroxybutyrate (BHB), a ketone.

How it works: The liver breaks down 1,3-butanediol, the same way it breaks down alcohol, into BHB, the main ketone in the blood. The (R) form of the molecule makes the natural D form of BHB.

Approval history: Not a drug. Allowed in US food as a liquid that carries flavourings. Sold in ketone supplement products. Not approved for any use. The lifespan result from the Interventions Testing Program (ITP), a US government-funded mouse study, is unclear. Females lived 2 percent longer by the standard test, but only at some test sites. Males lived 9 percent longer, but only by one other test (the Gehan test). The mice got it as 10 percent of their diet.

Licenses medicines for sale in the UK. A compound without a licence to be sold (a marketing authorisation) is an unlicensed medicine. The law only lets it reach people through a prescriber, under the specials scheme (unlicensed medicines made for one patient's needs). It cannot be sold as a research product.

The legal category above is how The Longevity Archive reads Medicines and Healthcare products Regulatory Agency listings for (R/S)-1,3-Butanediol on the reviewed date. It is not a legal opinion. Rules change. Bringing a compound into the country, prescribing it and owning it can each be treated differently. Check with the agency before you act on anything here.

Check MHRA directly

Whether (R/S)-1,3-Butanediol is banned in sport is set by the World Anti-Doping Code and by military rules, not by its legal status in the United Kingdom. Before you compete or get tested, look up (R/S)-1,3-Butanediol by name on the Prohibited List, or look up a named product in Global DRO. Under the World Anti-Doping Code, category S0 bans, at all times, any drug-like substance that meets two tests. No other section of the List covers it. And no government health regulator anywhere has a current approval for it as a treatment in people. Many substances that are approved somewhere are banned by name in another section. So approval does not mean a substance is allowed in sport.

• WADA Prohibited List
• Global DRO (check a named product)
• USADA (US athletes)
• Operation Supplement Safety (US service members)

The rules you compete or serve under decide this, not this page.