Long-term use of progestogens--getting the balance right: molecular biology and the endometrium

The role of progestins in long-term treatment has recently been under scrutiny, in particular as their effects on organs other than the endometrium, such as the breast or the cardiovascular system, could give rise to undesirable reactions. The use of progestins in hormone replacement therapy has highlighted the importance of choice of progestin. Insights into the molecular biology of normal processes in the endometrium can help to find accurate markers for progestin effects and help select progestins with a better benefit-risk profile. Such insight can also lead to a better understanding of the etiology of menstrual and fertility disorders and ultimately to new therapeutic approaches.