Levoamphetamine (also levamfetamine, (R)-amphetamine or (−)-amphethamine) is a psychostimulant known to increase wakefulness and focus in association with decreased appetite and fatigue. Levoamphetamine is the levorotatory stereoisomer of the amphetamine molecule. It possesses much weaker dopaminergic activity than the dextrorotary isomer (dextroamphetamine) and acts as a selective releasing agent of norepinephrine, similarly to levomethamphetamine.
While consubstantial in activity overall, there is a well-documented difference in specific target of action and differentiation of potential medicinal application and clinical meaning existing between the two isomers of amphetamine: simple amphetamine, levoamphetamine, creates significantly greater vasopressor effect and pressure upon the circulatory system overall than its counterpart, activating the sub-encephalized and cardiovascular systems more powerfully, and thus potentially more dangerously, than the more central nervous system-oriented dextrorotary form. Levoamphetamine has been reported as creating a more "gritty" and "powerfully raw" feeling of dynamic potency, when in the past used alone, or now, e.g., as in Adderall, combined isomers; and there is greater anxiogenic side effect reported by many patients.