Salvia divinorum - aka the 'YouTube drug' - is banned in many countries around the world, but not in Britain. Is it as harmless as its users claim?
In a cluttered living room in south London, Lee Hogan, a sound engineer and part-time disc jockey, perches on the edge of a cheap leather armchair and bends his head towards a glass water pipe. A friend, kneeling on the floor, holds the stem of the pipe and uses a cigarette lighter to burn a tea-smelling herb. The herb glows red, and as it does so, Hogan places his mouth over the aperture of the pipe (better known as a 'bong' to those in the know). He breathes in deeply, taking a lung-full of smoke.