Barrier methods provide a physical barrier to semen entering the uterus and causing pregnancy. They are the only method that helps protect against sexually transmitted infections (STIs). They are not 100% effective for contraception or preventing STIs.
Condoms are about 98% effective with perfect use, but can be significantly less effective with typical use (82%). Standard condoms are made of latex. Using oil-based lubricants can damage latex condoms and make it more likely they will tear. Polyurethane condoms can be used in latex allergy.
Diaphragms and Cervical Caps
Diaphragms and cervical caps are silicone cups that fit over the cervix and prevent semen from entering the uterus. The woman fits them before having sex, and leaves them in place for at least 6 hours after sex. They should be used with spermicide gel the further reduce the risk of pregnancy.
When used perfectly with spermicide, diaphragms and cervical caps are around 95% effective at preventing pregnancy. They offer little protection against STIs, and condoms need to be used for STI protection.
Dental dams are used during oral sex to provide a barrier between the mouth and the vulva, vagina or anus. They are used to prevent infections that can be spread through oral sex, including:
- Herpes simplex 1 and 2
- HPV (human papillomavirus)
- E. coli
- Pubic lice
Last updated August 2020