On average, condoms are 80% to 95% effective in protecting people from HIV infection when used correctly with every act of sex. This means that condom use prevents 80% to 95% of HIV transmissions that would have occurred without condoms. (It does not mean that 5% to 20% of condom users will become infected with HIV.) For example, among 10,000 uninfected women whose partners have HIV, if each couple has vaginal sex just once and has no additional risk factors for infection, on average:  If all 10,000 did not use condoms, about 10 women would likelybecome infected with HIV.  If all 10,000 used condoms correctly, 1 or 2 women would likely become infected with HIV. The chances that a person who is exposed to HIV will become infected can vary greatly. These chances depend on the partner’s stage of HIV infection (early and late stages are more infectious), whether the person exposed has other STIs (increases susceptibility), male circumcision status (uncircumcised men are more likely to become infected with HIV), and pregnancy (women who are pregnant may be at higher risk of infection), among other factors. On average, women face twice the risk of infection, if exposed, that men do.

For best protection, a condom should be used with every act of sex. In some cases, however, occasional use can be protective. For example, if a person has a regular, faithful partner and has one act of sex outside of the relationship, using a condom for that one act can be very protective. For people who are exposed frequently to STIs, including HIV, however, using a condom only some of the time will offer limited protection.

Yes. STIs can be passed from one person to another during any sex act that inserts the penis into any part of another person’s body (penetration). Some sex acts are riskier than others. For example, the risk of becoming infected with HIV is 5 times higher with unprotected receptive anal sex than with unprotected receptive vaginal sex. When using a latex condom for anal sex, a water- or silicone-based lubricant is essential to help keep the condom from breaking.

Yes. Plastic condoms are expected to provide the same protection as latex condoms, but they have not been studied as thoroughly. Condoms made of animal membrane such as lambskin condoms (also called natural skin condoms) are not effective for preventing STIs, including HIV.

No. On average, about 2% of condoms break, tear, or slip off completely during sex, primarily because they are used incorrectly. Used properly, condoms seldom break. In some studies with higher breakage rates, often a few users experienced most of the breakage in the entire study. Other studies also suggest that, while most people use condoms correctly, there are a few who consistently misuse condoms, which leads to breaks or slips. Thus, it is important to teach people the right way to open, put on, and take off condoms and also to avoid practices that increase the risk of breakage.

If a condom slips or breaks, taking emergency contraceptive pills can reduce the risk that a woman will become pregnant. If exposure to HIV is likely, treatment with antiretroviral medications, where available, can help reduce HIV transmission. If exposure to other STIs is likely, a provider can treat presumptively for those STIs—that is, treat the client as if he or she were infected. Washing the penis does not help prevent STIs. Vaginal douching is not very effective in preventing pregnancy, and it increases a woman’s risk of acquiring STIs, including HIV, and pelvic inflammatory disease.

There is little evidence for the benefits of using 2 or more condoms. It is generally not recommended because of concerns that friction between the condoms could increase the chance of breakage.

Yes, male condoms are effective, but only if used correctly with every act of sex. When used consistently and correctly, only 2 of every 100 women whose partners use condoms become pregnant over the first year of use. Many people, however, do not use condoms every time they have sex or do not use them correctly. This reduces protection from pregnancy.

You can't get pregnant while breastfeeding, can you?