Excretory patterns of urinary free 11-hydroxycorticosteroids and total oestrogens throughout the normal menstrual cycle.

The excretion of urinary free 11-hydroxycorticosteroids and total oestrogens was studied daily in morning urine specimens throughout the menstrual cycle of six normal women (age range 18-24 years). The follicular phase of the cycle was characterised by apparently random fluctuations in the excretion of urinary free corticosteroids. However, after the mid-cycle oestrogen peak there occurred a significant drop in corticosteroid excretion, which then rose to a peak eight to 10 days after ovulation and was synchronous with the second oestrogen peak during the luteal phase.