Levonantradol is a synthetic cannabinoid analogue of delta (9)-tetrahydrocannabinol (delta(9)-THC) administered intramuscularly. It has antiemetic and anti-analgesic properties. Although its precise mechanism of action is unknown, levonantradol appears to bind and activate the cannabinoid receptors CB1 and/or CB2. Antiemetic effect of levonantradol significantly superior to chlorpromazine. However, its adverse central effects limit its utility. The main adverse events are drowsiness and dizziness. Levonantradol, administered intramuscularly to the patients suffering from postoperative pain, manifested significant analgesic efficacy. Analgesia persisted for more than 6 h with the 2.5 and 3 mg doses of levonantradol. Drowsiness was frequent but few other psychoactive effects were reported.