Modeling the potential benefit of an over-the-counter progestin-only pill in preventing unintended pregnancies in the U.S.

Objectives: To develop a model to estimate the possible impact of use of an over-the-counter (OTC) progestin-only pill (POP) on the number of unintended pregnancies in the United States.

Study Design: Using typical use failure rates (7% for POPs), we compared the expected number of unintended pregnancies for two theoretical cohorts of 100,000 women: one which purchased and used an OTC POP exclusively for contraception, the other using contraceptive methods at proportions obtained from an actual-use clinical trial simulating OTC use of norgestrel 0.075 mg (including 35% using no method and only 19% using hormonal contraception or long-acting contraceptives).