- To evaluate the acceptability of the regimen The study will enroll fertile women of reproductive age who have sex up to 6 days a month, are at low risk for sexually transmitted infections (STIs), have no contraindications to progestin-only oral contraceptives,have no serious contraindications to pregnancy, and are willing to use an investigational method of contraception as their only contraceptive method for 6.5 months (each tablet contains 0.75 mg LNG to be used after every sex act).