EFFECT OF A COMBINATION OF NORETHYNODREL AND MESTRANOL ON PLASMA LUTEINIZING HORMONE IN NORMAL WOMEN

Plasma luteinizing hormone (LH) levels were studied by radioimmunoassay during two consecutive menstrual cycles in 6 normal subjects. The first cycle served as a control cycle. The subjects received a combination of norethynodrel (5 mg.) and mestranol (0.075 mg.) daily during the following cycle. A midcycle surge of plasma LH was observed in every subject during the control cycle, but in none during the treated cycle. The basal levels of LH during the treated cycles were significantly lower than during the follicular phase of the control cycles. The mechanisms by which this oral contraceptive drug affects plasma LH are discussed. © 1969.