Supporting claims

“Dr. John Lee has miraculously brought forth the hidden secrets of using natural progesterone cream for hormone replacement therapy. This book is a must read for all women who have had a hysterectomy, premature menopause or are in perimenopause, or natural menopause. This book should also be read by all physicians specializing in women's reproductive disorders. Unopposed estrogen can produce problems for some women. Dr. John Lee gives women who are suffering through the side effects of estrogen replacement therapy another road to follow in relief of menopausal symptoms.”

Beyond unsupported testimonials, there is a paucity of evidence to corroborate the use of natural progesterone cream. Dr. Lee did note, however, when reviewing his personal files that 63 out of 100 menopausal women experienced an increase in spinal bone mineral density when treated with 20mg of transdermal progesterone.

A 1990 paper by Prior, published in Endocin Rev, demonstrated an increase in bone formation markers when subjects ingested medroxyprogesterone acetate (a synthetic progestin).

The best evidence favoring transdermal use of natural progesterone relates to hot flashes. Significant improvement of vasomotor symptoms were seen in a randomly assigned trial of 90 women.

In this study 25 of 30 women in the treatment group who complained of vasomotor symptoms improved compared to five out of 26 women in the placebo arm of the study. This difference was determined to be statistically significant.

Taking natural progesterone should, according to proponents, protect the endometrium from estrogenic stimulation. Proliferative changes of the endometrium are purported not to occur when natural progesterone is given.