Does testosterone affect the normal menstrual cycle?
In order to throw further light on the role of androgens in the aetiology of the polycystic ovary syndrome (PCO) we have examined the effect of artificially increasing serum testosterone levels on menstrual function in a group of ovulating women. Six women were studied who had either severe premenstrual syndrome or loss of libido for which they were treated with 100 mg testosterone by s.c. implantation. All had regular menstrual cycles. For 1 month before implantation serum LH, FSH, oestradiol (E2), progesterone and testosterone were measured three times per week. All women showed normal cyclical variation of LH, FSH, E2 and progesterone. Following implantation, three times weekly blood samples were taken during the first and third cycles. No patient had any disturbance of menstrual pattern. All continued to show cyclical changes of LH, FSH, E2 and progesterone. Serum E2 and progesterone were lower but not significantly so in the luteal phase of the treated cycles. This was despite a m