Is Neuropeptide Y legal in the United Kingdom?

The one big test in people was a year-long study of a pill that blocks one of its receptors, in 1,661 overweight and obese adults. They lost weight, but so little that the authors themselves called it not clinically meaningful. The only study that gave NPY itself to people sprayed it up the nose of 26 people with PTSD. In rodents, it is the strongest appetite booster known when injected into the brain.

Neuropeptide Y, or NPY, is one of the most common signal peptides in the brain. The nerves that run the fight-or-flight system also release it, along with noradrenaline.

How it works: NPY works through a family of receptors on cells. In people, four of them work: Y1, Y2, Y4 and Y5.

Approval history: NPY is a brain chemical your own body makes. It is not a drug, and there is no approved product containing it. No drug acting on any NPY receptor is approved for obesity or for any other use. An NPY nasal spray has been tested in people with PTSD in one early safety study.

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 Neuropeptide Y 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 Neuropeptide Y 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 Neuropeptide Y 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.