When smoked, crystal meth rapidly achieves high concentrations in the brain without the burdens of the intravenous route. The actions of methamphetamine are explained, as well as the potential role of dopamine in methamphetamine craving. The author, Kish, states that there is currently no medication approved for the treatment of methamphetamine addiction or meth addiction relapses, but potential therapeutic agents targeted to dopamine and non-dopamine systems are in clinical testing.