Answer: Progesterone today is available from plant sources. Natural micronized progesterone is an exact chemical duplicate of the progesterone that is normally produced by the ovary. Synthetic progesterone, called progestogen, mimics the action of the progesterone, but the body does not respond in the same way. Studies have shown that progestogen (e.g. Provera) actually reduces the level of progesterone in the blood stream. Progestogens are about 10 times stronger than natural progesterone.
Answer: Natural progesterone combines with progesterone receptor sites and does not have many of the undesirable effects seen with the much more potent synthetic forms. Breast soreness from water retention is a temporary side effect of taking a little bit more than you need. Temporary drowsiness can occur at even higher doses. Reducing the dose resolves these effects.
3. Are there any other disadvantages of taking natural progesterone?
Answer: It is short-acting so it may need to be taken more than just once daily. This is important to do mainly for cycling woman having periods. It is usually not necessary to dose more than once daily in post-menopausal women.
My favorite form of natural progesterone is the troche (tro'-kee or trosh). It is less expensive and absorbs more evenly and predictably than the commonly prescribed gelcaps and creams. But progesterone does have a bitter taste and is usually flavored with peppermint (many flavors are available) and a non-carbohydrate sweetener, stevia leaf extract. Portions of these troches dissolve between cheek and gum or under the tongue and absorb into and through the oral mucosa fairly quickly. Holding the saliva in the mouth for a few minutes before swallowing increases absorption a lot.
Softgels are available at a somewhat higher cost, partly because higher doses are necessary. The liver quickly destroys most of the progesterone that is swallowed.
4. Do I need progesterone if I have had my uterus removed?
Answer: If the intent of using progesterone is merely to slough off endometrial tissue, then progesterone would not be necessary. But there are many receptor sites for progesterone in the brain, for good reason. So, even without a uterine lining to maintain, natural progesterone offers impressive improvements in quality of life issues such as: hot flashes, headaches, insomnia, anxiety and depression with the resulting progressive tightening of muscles causing fatigue and stiffness. Progesterone helps bone density a little, but not as much as estrogen and testosterone do. These are important issues for women with and without a uterus. Finally, don't forget, progesterone counter balances several of the uncomfortable and risky effects of significant levels of unopposed estrogen - so, properly dosed, it can lower your cancer risk (breast and uterine mainly).