A study in the current issue of the American Journal of Psychiatry examines the administration of an over the counter dietary supplement, N-Acetylcystine, to facilitate cessation of cannabis use in adolescents. Participants receiving N-Acetylcystine had more than twice the odds (compared to placebo) of having negative urine toxicology for cannabis. This study is the first to show a positive outcome for pharmacotherapy in the treatment of cannabis dependency.