PIP: The efficacy and clinical acceptability of a new oral contraceptive (OC) Mercilon (20 mcg ethinyl estradiol + 150 mcg desogestrel) was investigated in 235 women during 1305 cycles in an open, noncomparative, multicenter study carried out by 37 French gynecologists. No pregnancies occurred and cycle control was good. Only 5.5% of the women studied discontinued this OC because of irregular bleeding. The incidence of subjective side effects such as breast tenderness, known to be estrogen-dependent, was very low. Total continuation rate for Mercilon was very high for a low-dose contraceptive at 86%. Because of its clinical characteristics, along with its already proven excellent metabolic acceptability, this OC can be prescribed as a 1st choice for women without contraindication against combined OCs. (author's modified)