The terminology surrounding progesterone replacement can create much confusion for patients and physicians alike, said Dr. Moskowitz.

In a recent article published in the Journal of the American Nutraceutical Association, she clarified the issue. Progesterone refers to a single molecule that is exactly identical to the hormone produced endogenously. This is also known as P4. Progestogen, refers to a category of hormone molecules—either natural or synthetic—that are not necessarily identical to progesterone, but have progesterone-like activity in the uterus. The term, Progestin, refers to synthetic progestogens.

“Progestins mimic the body’s progesterone closely enough to bind to progesterone receptor sites, but they do not deliver the full range of messages that a natural progesterone molecule would. A synthetic progesterone may have similar effects on the endometrium, yet can initiate widely different actions elsewhere in the body, such as the brain, gonadotropins, mineralocorticoid receptors, etc.”

There are many botanically-based progesterone products available today, most derived from saponins from soy and wild yam (Dioscorea villosa). These can be particularly beneficial to some women during the perimenopausal period in which progesterone levels can fall rapidly with the first anovulatory cycle. Progesterone treatment can help balance the effects of unopposed estrogen production. The most widely-used natural progesterone product is Pro-Gest, a cream, distributed exclusively through physicians by Women’s Group Formulas (www.transitionsforhealth.com)