A condom is a sheath made of latex, polyurethane, polyisoprene, or lambskin that creates a barrier between the penis and the vagina, anus, or mouth to protect against pregnancy and sexually-transmitted diseases. Male condoms that fit over the penis are the most commonly used, although there are condoms for females as well. The female condom looks like a flexible tube, and has one closed end which is inserted into the vagina and one open end that fits around the entrance of the vagina.
Using a condom during sexual activity is particularly important for couples who are not monogamous, since this presents an increased risk of contracting sexually-transmitted diseases, including HIV, syphilis, chlamydia, and gonorrhea. Choosing a condom for pregnancy protection is convenient for many couples because condoms do not require a prescription. They can be used at the time of sexual activity instead of requiring a daily, weekly, or monthly use like other birth control methods, such as birth control pills, patches, and vaginal rings.
Most people do not experience any negative reactions when using a condom, though some are allergic to the materials they are made from, especially latex. People with a latex allergy can choose condoms made from other materials. Lambskin condoms are made from sheep intestines and do not cause irritation for people with latex allergies, but they are not suitable for protection against sexually-transmitted diseases because they have small holes that the virus can slip through. The holes are too small for sperm, however, so these condoms are effective in protecting against pregnancy.
Couples who choose to use a condom have many choices. Condoms are available in many different brands, sizes, colors, and textures to suit different couples' preferences. Dry condoms are available, but lubricated condoms often make sexual activity more comfortable for both partners.
Most countries have agencies and organizations that regulate condom sales and test the products for quality. The World Health Organization has recommended requirements for condom quality that many countries follow. These procedures include testing the products for bursting pressure and to reveal defects that could render the products ineffective.
Female and male condoms should not be used simultaneously. Condoms that contain the spermicide nonoxynol-9 are not recommended for couples using condoms for anything other than protection against pregnancy because the chemical can increase the risk of contracting HIV. It's also important to put condoms on correctly according to the instructions to increase their effectiveness, which studies show ranges from 85 to 98 percent, depending on the brand and if they are properly used.