It was determined endurable, toxic and fatal doses of a new original anti-migraine medicine Tropoxin in tablet form at unitary oral and intraperitoneal introduction to outbreeding white mice and rats. Periods of intoxication and death of animals with a detailed description of the observed clinical picture were registered. The median fatal doses were identified: LD50 = 759 (645 - 893) mg/kg in female mice, LD50 = 864 (764 - 977) mg/kg in male mice at intraperitoneal introduction; LD50 = 1152 (686 - 1932) mg/kg in female mice, LD50 = 1006 (605 - 1673) mg/kg in male mice at oral introduction; LD50 = 490 (400 - 601) mg/kg in female rats, LD50 = 515 (507 - 524) mg/kg in male rats at intraperitoneal introduction. Tropoxin did not cause death of rats at oral introduction in a dose of up to 5 g/kg. It was determined that Tropoxin in tablet form at oral and intraperitoneal introduction concerns to low-toxic substances. According to classification Sidorov K.K. Tropoxin in tablet form may be related to 4th toxicity class.