The previous subject is obviously an endless one, but as this is the glossary of an herbal nature, let me assure you, virtually no plants have a direct steroid hormone-mimicking effect. There are a few notable exceptions with limited application, like Cimicifuga and Licorice. Plant steroids are usually called phytosterols, and, when they have any hormonal effect at all, it is usually to interfere with human hormone functions. Beta sitosterol, found in lots of food, interferes with the ability to absorb cholesterol from the diet. Corn oil and legumes are two well-endowed sources that can help lower cholesterol absorption. This is of only limited value, however, since cholesterol is readily manufactured in the body, and elevated cholesterol in the blood is often the result of internal hormone and neurologic stimulus, not the diet. Cannabis can act to interfere with androgenic hormones, and Taraxacum phytosterols can both block the synthesis of some new cholesterol by the liver and increase the excretion of cholesterol as bile acids; but other than that, plants offer little direct hormonal implication. The first method discovered for synthesizing pharmaceutical hormones used a saponin, diosgenin, and a five-step chemical degradation, to get to progesterone, and another, using stigmasterol and bacterial culturing, to get to cortisol. These were chemical procedures that have nothing to do with human synthesis of such hormones, and the plants used for the starting materials-Mexican Wild Yam, Agave, and Soy were nothing more than commercially feasible sources of compounds widely distributed in the plant kingdom. A clever biochemist could obtain testosterone from potato sterols, but no one would be likely to make the leap of faith that eating potatoes makes you manly (or less womanly), and there is no reason to presume that Wild Yam (Dioscorea) has any progesterone effects in humans. First, the method of synthesis from diosgenin to progesterone has nothing to do with human synthesis of the corpus luteum hormone; second, oral progesterone has virtually no effect since it is rapidly digested; and third, orally active synthetic progesterones such as norethindrone are test-tube born, and never saw a Wild Yam. The only “precursor” the ovaries, testes and adrenal cortices EVER need (and the ONLY one that they can use if synthesizing from scratch) is something almost NONE of us ever run out of...Low Density Cholesterol. Unless you are grimly fasting, anorectic, alcoholic, seriously ill or training for a triathlon, you only need blood to make steroid hormones from. If hormones are off, it isn’t from any lack of building materials...and any product claiming to supply “precursors” better contain lard or butter (they don’t)...or they are profoundly mistaken, or worse. The recent gaggle of “Wild Yam” creams actually do contain some Wild Yam. (Dioscorea villosa, NOT even the old plant source of diosgenin, D. mexicana...if you are going to make these mistakes, at least get the PLANT right) This is a useful and once widely used antispasmodic herb...I have had great success using it for my three separate bouts with kidney stones...until I learned to drink more water and alkalizing teas and NEVER stay in a hot tub for three hours. What these various Wild Yam creams DO contain, is Natural Progesterone. Although this is inactive orally (oral progesterone is really a synthetic relative of testosterone), it IS active when injected...or, to a lesser degree, when applied topically. This is pharmaceutical progesterone, synthesized from stigmasterol, an inexpensive (soy-bean oil) starting substance, and, although it is identical to ovarian progesterone, it is a completely manufactured pharmaceutical. Taking advantage of an FDA loophole (to them this is only a cosmetic use...they have the misguided belief that it is not bioactive topically), coupled with some rather convincing (if irregular) studies showing the anti-osteoporotic value of topical progesterone for SOME women, a dozen or so manufacturers are marketing synthetic Natural Progesterone for topical use, yet inferring that Wild Yam is what’s doing good. I am not taking issue with the use of topical progesterone. It takes advantage of the natural slow release into the bloodstream of ANY steroid hormones that have been absorbed into subcutaneous adipose tissue. It enters the blood from general circulation the same way normal extra-ovarian estradiol is released, and this is philosophically (and physiologically) preferable to oral steroids, cagily constructed to blast on through the liver before it can break them down. This causes the liver to react FIRST to the hormones, instead of, if the source is general circulation, LAST. My objection is both moral and herbal: the user may believe hormonal effects are “natural”, the Wild Yam somehow supplying “precursors” her body can use if needed, rejected if not. This implies self-empowerment, the honoring of a woman’s metabolic choice...something often lacking in medicine. This is a cheat. The creams supply a steady source of pharmaceutical hormone (no precursor here) , but they are being SOLD as if the benefits alone come from the Wild Yam extract, seemingly formulated with the intent of having Wild Yam the most abundant substance so it can be listed first in the list of constituents. I have even seen the pharmaceutical Natural Progesterone labeled as “Wild Yam Progesterone” or “Wild Yam Estrogen precursor” or, with utter fraud, “Wild Yam Hormone”. To my knowledge, the use of Mexican Yam for its saponins ceased to be important by the early 1960’s, with other processes for synthesizing steroids proving to be cheaper and more reliable. I have been unable to find ANY manufacturer of progesterone that has used the old Marker Degradation Method and/or diosgenin (from whatever Dioscorea) within the last twenty years. Just think of it as a low-tech, non invasive and non-prescription source of progesterone, applied topically and having a slow release of moderate amounts of the hormone. Read some of the reputable monographs on its use, make your choice based solely on the presence of the synthetic hormone, and use it or don’t. It has helped some women indefinitely, for others it helped various symptoms for a month or two and then stopped working, for still other women I have spoken with it caused unpleasant symptoms until they ceased its use. Since marketing a product means selling as much as possible and (understandably) presenting only the product’s positive aspects, it would be better to try and find the parameters of “use” or “don’t use” from articles, monographs, and best of all, other women who have used it. Then ask them again in a month or two and see if their personal evaluation has changed. If you have some bad uterine cramps, however, feel free to try some Wild Yam itself...it often helps. Unless there is organic disease, hormones are off is because the whole body is making the wrong choices in the hormones it does or doesn’t make. It’s a constitutional or metabolic or dietary or life-stress problem, not something akin to a lack of essential amino acids or essential fatty acids that will clear up if only you supply some mythic plant-derived “precursor”. End of tirade.