At present, the Mexican mint Salvia divinorum is an unregulated hallucinogen. This has resulted in various on-line botanical companies advertising and selling S. divinorum as a legal alternative to other regulated plant hallucinogens. It is predictable that its misuse will increase rapidly. The active ingredient in S. divinorum is the neoclerodane diterpene, salvinorin A (1a), which has been shown to be a kappa agonist both in vitro and in vivo. This review will cover the current state of research into the psychopharmacology of S. divinorum.