Several studies have demonstrated that male condoms made of either latex or polyurethane are effective barriers against HIV. The theory behind using condoms is clear: they cover the penis and provide an effective barrier to secretions such as semen and vaginal fluids, thereby blocking sexual transmission of HIV infection.
Studies have also demonstrated that other common sexually transmitted viral infections, such as herpes simplex virus (HSV) and hepatitis B virus (HBV), can be prevented with the use of latex or polyurethane condoms. While condoms can help prevent the transmission of human papillomavirus (HPV), a virus that can cause cervical and penile warts, lesions and cancer, there is still a risk of infection.
Condoms made of "natural" materials—such as lambskin—are not a consistently effective barrier against many viruses. This is because they contain microscopic holes through which HIV can pass.
The key to effective protection is consistent and correct use of condoms. To learn more about correct condom use, click here.
Incorrect use of condoms can increase the risk of condom slippage or breakage, which diminishes their protective effect. Inconsistent use—for example, failure to use condoms with every act of vaginal or anal intercourse—can lead to HIV transmission.
A word about polyurethane condoms: They are an effective alternative to latex condoms, especially for people with an allergy to latex. However, some studies have found that polyurethane condoms are more likely to break than latex condoms. Still, if used consistently and correctly, they are considered to be a highly effective barrier against the sexual transmission of HIV.
The female condom, approved in 1993 for use in the United States, is a polyurethane pouch with flexible polyurethane rings at each end. It is inserted deep in the vagina, much like a diaphragm. The ring at the closed end holds the pouch in the vagina. The ring at the open end stays outside the vulva (vaginal opening). If inserted properly, it lines the vagina and the cervix, which helps to prevent pregnancy, along with HIV and other sexually transmitted infections.
While female condoms are not approved for use during anal intercourse, some men and women have reported using them for anal sex. However, at least one study has uncovered problems for the receptive partner using the female condom, during anal sex, including difficulty inserting the condom, discomfort and rectal bleeding (removing the inner ring may alleviate some of the problems experienced during anal insertion and removal).
A Word About Lubricants
Only water-based and silicone-based lubricants should be used with latex condoms. K-Y Jelly, Wet and Astroglide are three examples of water-based lubricants that can be used with latex condoms. Examples of silicone-based lubricants include Millennium ID and Eros Bodyglide.
Never use oil-based lubricants, including hand or body lotion, baby oil, vegetable oil or shortening, massage oil, mineral oil, or petroleum jelly (e.g., Vaseline) with latex condoms. Oil-based lubricants can damage latex and cause latex condoms to tear more easily. If you must use an oil-based lubricant, it should only be used with polyurethane condoms.
Some pre-lubricated condoms and separately sold lubricants contain a chemical called nonoxynol-9. While nonoxynol-9 has been shown to kill sperm (and potentially reduce the risk of pregnancy) and various sexually transmitted infections, some men and women are allergic to this chemical. This can cause irritation inside the vagina and anus, which can increase the risk of HIV transmission if the condom breaks.