As I research, it looks like the main base for Natpro is derived from soy. One of your responses indicates that there is no soy, only yam, yet it is also stated on a page that Natpro is not a yam "extract." Could you please clarify?
Although this web site is not intended to be prescriptive, it is intended, and hoped, that it will induce in you a sufficient level of scepticism about some health care practices to impel you to seek out medical advice that is not captive to purely commercial interests, or blinded by academic and institutional hubris. You are encouraged to refer any health problem to a health care practitioner and, in reference to any information contained in this web site, preferably one with specific knowledge of progesterone therapy.