Fifty women were treated over 550 menstrual cycles with a long-acting injectable mixture of 25 mg norgestrel and 5 mg estradiol hexa-hydro-benzoate administered monthly. The treatment proved to produce sterility in all patients when injections were given between 28 and 30 day intervals. Minor changes in menstrual pattern were reported but cyclic bleeding similar to menstruation was preserved in 75% of all the cycles.
