Clinical trial of a long-acting injectable contraceptive: NET-EN.

Injectable progestogen, norethisterone enanthate (NET-EN, 200 mg/ml) was administered to 122 women at 2 month intervals for more than 1 year. Only a minority of women had consistently normal cycles. Most women experienced some menstrual irregularities: 57% of users experienced irregular bleeding, 32% developed amenorrhea, while only 11% showed regular cyclic bleeding. Important nonmenstrual side effects were weakness and abdominal pain. No appreciable changes in body weight and blood pressure were recorded.