Effectiveness: 85 to 98 percent; effectiveness is reduced if it slips or tears (2-18 pregnancies per 100 women each year).
What is it? Also called a "rubber," it is usually a thin latex, silicone or polyurethane cover that fits over the hard penis. It may also be made of natural membranes, such as lambskin. Many other variations are available, such as lubricated or non-lubricated, ribbed or smooth, brightly colored, clear or flavored.
How does it work? It traps sperm in the condom so it can't enter your body. It should be placed on the tip of your partner's erect penis and unrolled to the base. An empty space at the tip holds the semen. It should be put on before genital contact and carefully removed after intercourse, holding the base so it doesn't slip.
STD protection: Yes, latex, silicone and other synthetic condoms protect against most STDs though they aren't guaranteed protection against all. Natural membrane condoms, such as lambskin, protect against bacterial infections, such as chlamydia and syphilis, but may not protect against viral infections.
Benefits: Latex or polyurethane condoms block HIV and other STDs. They are very effective at preventing pregnancy when used with spermicides and used correctly. They are easily available and affordable and can be used for vaginal, anal or oral sex.
Disadvantages: Condoms may decrease you or your partner's sensitivity, and some men lose erection while putting on the condom. Possible latex allergy. Natural membrane condoms don't prevent STDs.
Availability: Inexpensive and readily available at drugstores, vending machines and other places. Sometimes available for free.
Cost: About $1 each.*
Notes: Condoms are very effective if they don't slip or tear so use lubricants to make them less likely to tear and to increase pleasure. Check the expiration date; old condoms may deteriorate and tear.
* The Affordable Care Act requires insurance companies to cover with no co-pay any FDA-approved contraceptive method prescribed by your doctor, including barrier methods, hormonal methods, implanted methods, emergency contraception, female sterilization and patient education and counseling. These estimated costs apply to women who do not have insurance coverage or who work for a "religious employer," who may be exempt from providing contraceptive coverage. For details about what your insurance covers, contact your benefits coordinator or health insurance provider.