Abstract
A 21-day treatment cycle oral contraceptive of variable composition was administered to 68 healthy young women, each of whom completed 6 cycles of treatment. For the first 11 days, the product contained 50 fig levonorgestrel plus 50 fig ethinyl oestradiol, then for treatment days 12 to 21, 125 fig levonorgestrel plus 50 fig ethinyl oestradiol. Cycle control was good with a mean length of 27.9±1.1 days. Breakthrough bleeding occurred in 1.2% of cycles, spotting in 2.8%, and amenorrhoea in 0.5%. There were no serious side-effects. A series of biochemical tests conducted on fasting blood specimens indicated metabolic changes similar to those seen with other 50 fig oestrogen oral contraceptives.