Studies of the internal condom show that it, if used perfectly, 5% of users will experience a pregnancy within the first year of use. In typical use (which includes imperfect insertion and inconsistent use), 21% of users will experience a pregnancy within the first year. The rate of breaks or tears in the internal condom is less than 1%, compared to 4% with the external condom.

Like the external condom, the internal condom provides good but not complete protection against all STIs. Infections that are transmitted through skin to skin contact-- such as herpes or HPV (genital warts) may still be transmitted via areas of the skin that are not covered by the condom.