The Football Association has warned clubs and club doctors about a rogue substance that is said to be trading on the black market.
GW501516 is a substance that has "serious toxicities" because of failings during development.
A statement on the FA's website read: "Following a statement released by the World Anti-Doping Agency (WADA), The FA has written to clubs and club doctors to warn players about a substance that is currently available on the black market.
"The substance known as GW501516 was a developmental drug that was withdrawn and terminated from research by the pharmaceutical company when serious toxicities were discovered in pre-clinical studies.
"Some Anti-Doping Organisations around the world have reported its use by athletes."
UEFA released a similar statement earlier today after the announcement from WADA.
Written by
Pascal Lemesre
Pascal Lemesre
