Home Secretary Jacqui Smith has asked the Advisory Council on the Misuse of Drugs to consider whether Spice and other substances that produce "legal highs" should be made illegal, The Times of London reported Friday.
An import from China, three grams of Spice sell for $37.50 in Britain.
Council member Les King told a drug conference in Portugal that the synthetic additives in Spice mimic the effects of THC, the psychoactive substance that gives cannabis its high.
King will present the latest evidence on Spice to the council next week.
Other legal substances the council will discuss include the psychoactive herb Salvia divinorum, a hallucinogen cited as a contributory factor in teenage suicides.
Salvia, which is sold over the Internet, is said to cause uncontrollable laughter and evoke childhood memories.