The toxic effects of sterigmatocystin are much the same as those of aflatoxin B1. It is thus considered as a potent carcinogen, mutagen, and teratogen. It is less acutely toxic to rodents and monkeys but appears to be slightly more toxic to zebra fish. The LD50 in mice is in excess of 800 mg/kg. The 10-day LD50 in Wistar rats is 166 mg/kg in males, 120 mg/kg in females, and 60-65 mg/kg for ip. administration in males. The ip. 10-day LD50 for vervet monkeys is 32 mg/kg.