The history and rationale of hormone replacement therapy.

Robert Wilson rendered women aged over 45 a great service. He provoked a line of research which has in 25 years resulted in a sensible approach towards the use of medication in treating the climacteric and post-menopausal oestrogen deficiency. The history of hormone replacement therapy (HRT) is described, as is the current approach to rational HRT. Some ideas are outlined for future development.