Oral tretinoin has actually been proven for being teratogenic in rats, mice, hamsters, and subhuman primates. It was teratogenic and fetotoxic in Wistar rats when given orally or topically in doses better than 1 mg/kg/working day (eight moments the most human systemic dose adjusted for complete human body area location). https://www.wiredprnews.com/tretinoin-creams-uk-launches-new-website/