A condom is a barrier method of protection made of latex (rubber) or polyurethane. It covers the penis and collects semen and other fluids, preventing them from entering a woman’s vagina.
With typical use, 15 women in 100 (15%) become pregnant in one year. With perfect use, 2 women in 100 (2%) will become pregnant in one year.
When used correctly and consistently from beginning to end, condoms are the only method that protects against both pregnancy and STDs, including HIV. Plus, you don’t need a prescription, and they are cheap and easy to find at any drugstore.
Condoms can leak or break if not put on or taken off correctly or if the wrong size. Oil-based lubricants (like Vaseline or massage oil) should not be used because these kinds of lubricants can cause condoms to break during sex.