Is it common to experience hair loss when using prometrium (micronized progesterone) or estradiol.

Yes, it happens: The study results one study indicate that estrogen and Progesterone receptor expression is not significantly increased or decreased in the pilosebaceous units or surrounding mesenchymal cells in androgenic alopecia vs. Alopecia areata. Therefore, an indirectly mediated process of estrogen/progesterone control on hair growth and development must be presumed for cases of androgenic alopecia.