Progesterone has a number of side effects including increasing aggression, killing the libido and it activates the human paipilloma virus (HPV). HPV has been linked to cervical, breast, prostate, nasophayngeal and skin cancers. I don't think any person should be on progesterone creams except in some very rare circumstances, such as severe endometriosis, and even at that only short term.
Another thing that the sales sites don't mention is the fact that progesterone creams build up in the fat tissues. They are not out of the body within 24 hours as many of the sites claim. Women who have used progesterone creams for more than a few years can more than a 6 year supply of progesterone built up in their fat cells.