WOMEN wearing hormone replacement therapy skin patches should remove them before undertaking vigorous exercise, according to Australian doctors. They describe in the Lancet the case of a woman who had been using the patches for six months and who started to suffer severe headaches after aerobics classes. Removing the patch before exercising solved the problem.

The doctors suggest that exercise can dilate blood vessels and increase the absorption of oestrogen from the patch, precipitating a vascular headache.