Acteoside (verbascoside) was isolated as an analgesic principle from Cedron (leaves and stem of Lippia triphylla (L'HER) O. KUNTZE; Verbenaceae), a Peruvian medicinal plant, by activity-guided separation. The compound exhibited analgesia on acetic acid-induced writhing and on tail pressure pain in mice by the oral administration of 300 mg/kg and 100 mg/kg, respectively. Acteoside also caused weak sedation by its effect on the prolongation of pentobarbital-induced anesthesia and on the depression of locomotion enhanced by methamphetamine. An intravenous injection of acteoside reduced the effective dose to 2 mg/kg by the writhing method. Thirteen related compounds were tested for the activity by intravenous and oral administration to obtain information on the active structure.