The following has been composed to help clear up the confusion over the
efficacy or proper use of Yam extract (Dioscorea Villosa) and Natural Progesterone.
Because we were the first site on the Internet to offer educational information on natural progestereone cream, we have received many letters from women who are suffering due to the fact that they have not responded to a variety of traditional treatments or have been using a "yam cream." Complicating matters is the fact that a number of companies in the U. S., are claiming or implying that their "yam creams" contain Natural Progesterone, when, in fact, an examination of their ingredients reveals that they only contain Wild Mexican Yam extract. In fact, some companies have even stated: "This plant makes a substance identical to the progesterone produced by the human body.!"
All of the research that we have reviewed on Progesterone demonstrates that it is supplemental Natural Progesterone that will produce an increase in saliva & serum levels of progesterone, not Yam extract. (It is important to note that Yam contains plant saponins that have been shown to benefit women's health. However, what is at issue are biological progesterone levels and progesterone's balancing effects on estrogen and subsequent relief from the symptoms of Menopause & PMS and its ability to correct the conditions of Infertility & Osteoporosis.)
In his current book, "What Your Dr. May Not Tell You About Menopause" on page 270, Dr. Lee states "…there is no evidence that the human body converts diosgenin (found in Mexican Wild Yam) to hormones." Dr. David Zava, (PhD in Bio Endocrinology whose focus has been progesterone and estrogen receptor activity) is the laboratory director of Aeron LIfe Cycles, one the foremost hormone testing facilities in the world. Dr. Zava has tested progesterone levels for many thousands of women and responded with the following: "In response to your question about wild yam steroids - do they convert into progesterone? The answer is no, there are no enzymes in the human body that will convert diosgenin, the active component of wild yams, into progesterone. This does not mean diosgenin is without activity in the body as it has been used by phytotherapists for centuries as an adaptagen."
As a further disservice to the women who suffer with the symptoms brought on by "estrogen dominance" some company representatives will tell you that Yam extract (diosgenin) is molecularly the same as Natural Progesterone and that users of their "progesterone cream" will find the same benefit as they would with a cream that really contains USP Natural Progesterone.
The current published research and clinical experience do not support that claim.*
*A review of the Med-Line Database (5/1/95 & 4/10/96) bought up more than 5,000 published studies completed on "Progesterone" between 1992 & 1996. (k=progesterone)