Levomethamphetamine is the levoratory (L-enantiomer) form of methamphetamine. It is a sympathomimetic vasoconstrictor which is active ingredient in some over-the-counter nasal decongestant inhalers in the USA.

‘Levo’ crosses the blood-brain-barrier and acts as a TAAR1 agonist, functioning as a selective norepinephrine releasing agent, so it affects the central nervous system (with no effects on the release of dopamine) although its effects are qualitatively distinct relative to those of of dextromethamphtamine.

‘Levo’ does NOT possess the potential for euphoria or addiction that ‘dextro’ possesses. Among its physiological effects are the vasoconstriction that makes it useful as a nasal decongestant.

The elimination half-life of levomethampehtamine is between 14 and 15 hours, while dextromethamphetamine has a half-life of about 10 hours.