What Is It?
A condom is a thin latex (a type of rubber) sheath that is worn on the penis. A condom is also often called a "rubber" or "prophylactic."

How Does It Work?
The condom works by keeping semen from entering the vagina. It is placed on a guy's penis when it becomes erect. It is unrolled all the way to the base of the penis while holding the tip of the condom to leave some extra rubber. This creates a space for semen after ejaculation and makes it less likely that the condom will break.

After the guy ejaculates, he should hold the condom at the base of the penis as he pulls out of the vagina. He must do this while the penis is still erect to prevent the condom from slipping off when he gets soft. If this happens, sperm could enter the vagina.

A used condom should be thrown in the garbage, not down the toilet. Once a condom is used, it cannot be reused. A new condom should be used each time you have sex and it must be used from start to finish every time you have sex to prevent pregnancy and sexually transmitted diseases. Never use oil-based lubricants such as mineral oil, petroleum jelly, or baby oil with condoms because the these substances can break down the rubber. And if a condom ever seems dry, sticky, or stiff when it comes out of the package, or if it is past its expiration date, throw it away and use a new one. It's a good idea to have several condoms on hand in case there is a problem with one. It's best to store unused condoms in a cool, dry place.

How Well Does It Work?
Over the course of 1 year, 15 out of 100 typical couples who rely on condoms alone to prevent pregnancy will have an accidental pregnancy. Of course, these are average figures and the chance of getting pregnant depends on whether you use this method correctly and every time you have sex. Using spermicide along with condoms will provide added protection against pregnancy, especially if the condom slips or breaks during sex.

In general, how well each type of birth control method works depends on a lot of things. These include whether a person has any health conditions or is taking any medications that might interfere with its use. It also depends on whether the method chosen is convenient - and whether the person remembers to use it correctly all the time.

Protection Against STDs
Most condoms are made of latex. Those made of lambskin may offer less protection against some sexually transmitted diseases (STDs), including HIV, so use of latex condoms is recommended. For people who may have an allergic skin reaction to latex, condoms made of polyurethane are available.

When properly used, latex and plastic condoms are effective against most STDs. Condoms do not protect against infections spread from sores on the skin not covered by a condom (such as the base of the penis or scrotum). For those having sex, condoms must always be used to protect against STDs even when using another method of birth control.

Possible Side Effects
Most men and women have no problems using condoms. The side effects that can occasionally occur include:

• allergy to latex condoms
• irritation of the penis or the vagina from spermicides or lubricants that some condoms are treated with

Who Uses It?
Couples who are responsible enough to stop and put a condom on each time before sex and people who want protection against STDs use condoms. Because condoms are the only method of birth control currently available for men, they allow the guy to take responsibility for birth control and STD protection. Condoms are also a good choice for people who do not have a lot of money to spend on birth control.

How Do You Get It?
Condoms are available without a prescription and are sold in drugstores, supermarkets, and even vending machines. (In some stores, they will be in an aisle that's called "Family Planning.") Condom choices are pretty varied: they come in different sizes, textures, colors, and flavors. Some are lubricated and many are coated with spermicide as well, although using separate vaginal spermicide is more effective.

How Much Does It Cost?
Condoms are the least expensive and most available method of birth control. Condoms cost about 50 cents to $1 each and are less expensive when they are bought in bigger boxes. In addition, many health centers and family planning clinics (such as Planned Parenthood) and some schools distribute them free of charge.

Remember, abstinence (the decision to not have sex) is the only method that always prevents pregnancy and sexually transmitted diseases.