I've seen it marked either as "USP progesterone" or "bioidentical progesterone". Depends on the brand. The cream I have right now is Pro-Gest made by Life-flo. Label mentions USP progesterone without mentioning its source. This one is just as good as Biovea brand which has similar ingredients, but it absorbs somewhat better. Its on same concentration too, 20mg Prog per quarter teaspoon.