It's a synthetic progestin rather than a bioidentical progesterone. It's not processed by the body in exactly the same way as a bioidentical. Because of this, some people have unwanted side effects from it, but at the same time many don't. I've been on Medroxy for almost a year and haven't noticed anything bad. However, I do think it would be preferred to get on a bioidentical like Prometrium instead if you have the option.
