Several European studies have been conducted to confirm the efficacy, tolerability, and safety of a new oral contraceptive (OC) combining 250 micrograms norgestimate with 35 micrograms ethinyl estradiol (Ortho-Cyclen or Cilest). In a 12-month multicenter German study of 147 women, treatment with this formulation resulted in no pregnancies, a low incidence of side effects, and excellent cycle control. The drug had no effect on estrogen-mediated fibrin formation nor on the activity of coagulation inhibiting or promoting factors. Similarly, the documented low androgenicity of the highly selective progestational agent norgestimate results in a more positive metabolic profile. Glucose, insulin, and hemoglobin A1c concentrations measured before and after glucose loading were not adversely affected by treatment with the norgestimate-containing OC, and all changes were reversible on its discontinuation. In addition, lipid metabolism was positively influenced by the drug. Low-density lipoprotein cholesterol, a known risk factor for cardiovascular disease, was reduced while the cardioprotective lipid fraction, high-density lipoprotein cholesterol, was increased. Clinical trials to determine the OC's effects on coagulation, endocrine function, and carbohydrate and lipid metabolism are reviewed. Also discussed are several studies demonstrating the formulation's unique endometrial effects, which may possibly be related to its low androgenic activity and consequent low incidence of breakthrough bleeding and amenorrhea.