Barrier methods have the advantage of not only preventing pregnancy, but also provide some protection against sexually transmitted diseases. They work by preventing the sperm from getting to the egg. The male condom is widely available, and can be very effective if used properly. The most common cause of failure is a tear caused by a fingernail, so be careful when putting a condom on. Emergency contraception can be used for backup in case of a condom failure.
Most condoms are latex rubber.
There are also condoms that a woman can wear internally. Some are available without prescription, such as foam, gels, suppositories, film, creams or tablets. They need to be placed in the woman's vagina a few minutes before intercourse. If the woman uses a spermacide and the man wears a condom, there is very good protection both against pregnancy and against diseases. Two other barrier methods need to be fitted by a health care professional.