- NOTE: Acceptable methods of contraception may include one or more of the following: 1) male partner who is sterile prior to the female subject s entry into the study and is the sole sexual partner for the female subject; 2) implants of levonorgestrel; 3) injectable progestogen, an intrauterine device with a documented failure rate of less than 1percent; 4) oral contraceptives; and 5) double barrier methods including diaphragm or condom with a spermicide.