Contraceptive Steroids and Sexual Activity

Abstract

STUDIES on the sexual behaviour of higher primates with compounds currently used for oral contraception have relevance for humans. To date, however, no behavioural experiments in this area have been reported. Old world monkeys and apes alone among mammals, but like women, have a true menstruation with a cycle of about 28 days, and rhythmic changes in the sexual activity of male rhesus monkeys are known to occur in relation to the menstrual cycle of the female of the pair^1–3: somewhat similar changes in sexual activity have recently been described in relation to the menstrual cycle of women^4,5. The administration of oestradiol to ovariectomized rhesus monkeys stimulates the copulatory activity of males while the subsequent administration of progesterone depresses it⁶, thereby reproducing the behavioural changes occurring with intact females during the menstrual cycle. We describe here some changes in the sexual activity of male rhesus monkeys during the treatment of their female partners with combinations of an oestrogen and two progestins currently used by women for oral contraception.