In a study recently published in The Journal of Clinical Pharmacology, (June 2005) researchers found substantial evidence that use of OTC topical progesterone results in similar drug exposure through skin absorption as that which results from taking a prescribed oral progesterone product.
The Bassett Healthcare supported study, led by Drs. Anne C. Hermann, Anne Nafziger and Joseph Bertino, consisted of twelve, healthy, post-menopausal women. Each subject was treated with topical OTC progesterone (Pro-gest cream) in one phase and prescribed oral progesterone (Prometrium) in the other phase of the study. According to the results, there was no difference between the two groups in the amount of progesterone exposure in the body. The women involved in this study also experienced similar rates of adverse effects while taking each type of progesterone. This study differed from previous studies because of its use of more precise and advanced drug analysis methods, giving results that are accurate compared to previous studies with topical progesterone products.