Cannabis

Cannabis (also known as wacky backy) was a drug.

Jack Harkness and Owen Harper once investigated a village where a number of people's hair turned blue, finding that it was caused by cannabis contaminated with lazulium. (AUDIO: Expectant)

Rhys Williams occasionally used the drug. (AUDIO: Visiting Hours)

By 2069, cannabis cigarettes were legal and were produced in Birmingham. (PROSE: Alien Bodies)