Thebaine is far more toxic (ten times higher) than morphine. Compared to morphine sulfate, thebaine is 10 times more lethal: Morphine sulfate anhydrous: oral rat LD50
: 461 mg/kg; oral mouse LD50: 600 mg/kg!
(!) Thebaine is the most poisonous opium alkaloid!
The UNHDOC mentioned that the LD. 50 of Thebaine in mice is 31 mg/kg s.c. and 20 mg/kg i.p.; other authors have reported an intraperitoneal
(the area that contains the abdominal organs.) LD 50 of 42 mg/kg in mice.
In rabbits, the intravenous LD 50 is 3-4 mg/kg and is dependent on the age of the animals. In the dog the lethal doses are reported to be 10-30 mg/kg s.c. and 5-7 mg/kg i.v.. In chicken embryo, Thebaine has been reported to induce pseudohyperfeminization (change of the Gender-features).