The word progesterone is too often incorrectly used when referring to progestational substances - both natural progesterone and synthetic progestins. They are not the same and have different effects in the body. Synthetic hormones are accompanied by numerous and dangerous side effects, while natural progesterone has very few.
(as listed in the 1994 PDR):
Acute allergic reaction
Rise in blood pressure
Alopecia (hair loss)
Changes in libido
At age 20, DHEA levels begin to drop...
fromSmart & Nutrientby Dr. Ward Dean