Most people know that condoms serve the dual purpose of protecting against sexually transmitted diseases and preventing pregnancy. But in a recent survey from the American Sexual Health Association, up to 40 percent of women say they're more likely to have sex without a condom if they've been drinking. The survey tallied results from 925 women aged 16 to 25 and found that only a third of them would pack a condom before a night out, and just half of the women would feel comfortable buying condoms. Another study in the Journal of Adolescent Health found that women who start using oral contraceptives for birth control typically stop using condoms. While preventing pregnancy is a benefit, protection against STDs doesn't happen when oral contraceptives are the only method of protection.