Progesterone and related progestins: potential new health benefits

Abstract

Progesterone is a steroid hormone that is essential for the regulation of reproductive function. The main physiological roles of this hormone have been widely described. Progesterone and progestins have been approved for a number of indications including the treatment of irregular and anovulatory menstrual cycles and, when combined with estrogen, for contraception, and the prevention of endometrial hyperplasia in postmenopausal hormonal replacement therapy (HRT) regimens. Lack of understanding between the differences in categories of the progestins as well as with the physiological hormone has resulted in considerable controversy surrounding the use of progestins for HRT regimens. Newer evidence suggests that there are distinct differences between the molecules and there is no progestin class effect, with regard to benefits or side-effects. In addition to its role in reproduction, progesterone regulates a number of biologically distinct processes in other tissues, particularly in the nervous system and the vessels. Recently, it has been shown in animal experiments that progesterone and the progestin Nestorone^® have positive effects on neuroregeneration and repair of brain damage, as well as myelin repair. The potential benefits of natural progesterone and its related derivatives warrant further investigation. It is hoped that a better understanding of the mechanism of action of progesterone and selected progestins will help in defining better therapies for men and women.

Key words::

• PROGESTERONE
• PROGESTIN
• NESTORONE
• NEUROREGENERATION
• MYELIN REPAIR
• STROKE
• HORMONE REPLACEMENT THERAPY
• LACTATION
• PROGESTERONE VAGINAL RING

ACKNOWLEDGEMENT

The authors thank Dr Lisa Cowen for her excellent help with science writing.

Conflict of interest M. E. E. has no conflict of interest to declare. R. S. W. is an employee of the Population Council, a not-for-profit organization developing the progesterone vaginal ring for lactating women. She also lectured and advised Bayer Pharma and Merck on progestins used as contraception.

Source of funding Some results described in this review were obtained under grants from USAID, NICHD and the Barrus Foundation. R. S. W. received support from the NIH for the work on the progesterone vaginal ring during lactation (5 ROI HD061106-04) and for the work on the action of progesterone and Nestorone on the brain (5U54HD029990).