Clinical evaluation of a new oral contraceptive, 'Pregnon'.

'Pregnon', a new oral contraceptive containing 1 mg. lynestrenol and 0.05 mg. ethinyl oestradiol, was administered cyclically to 639 women of fertile age over a total of 9,159 cycles. There were no pregnancies. In most cases the withdrawal bleeding resembled normal menstruation. The incidence of metrorrhagia was relatively low and when it did occur it was usually confined to the early treatment cycles and was of very limited duration. The objective and subjective tolerance was excellent.