Do they work?
Well, let’s look at the facts. Obviously they don’t work at all unless they’re used in the first place. And they don’t protect very well if they are used "inconsistently" or "incorrectly." In other words: you have to use them every single time — with no exceptions — and follow the Centers for Disease Control and Prevention (CDC) recommended seven steps to correct usage.

What if I use them most of the time?
You’re at risk. In fact, the CDC says, "Used inconsistently (less than 100 percent of the time), condoms offer little more protection than when they are not used at all." Good intentions won’t protect you. About 15 percent of couples who rely on condoms to avoid pregnancy will still get pregnant within the first year of use. And even if you manage to use them consistently and correctly, 2 - 4 percent of condoms leak, break, or slip off. And you’re not just at risk for pregnancy.

Do condoms prevent all STDs (Sexually Transmitted Diseases)?
An STD is a virus, bacteria or other small organism that can be acquired through sexual contact with someone who has the disease. Some have cures. Some do not. Some are relatively harmless if treated. Some are deadly. Condoms reduce the risk but do NOT eliminate the risk of acquiring such STDs as HIV and gonorrhea. They’re even less effective at preventing genital herpes, trichomoniasis and chlamydia. Plus, they offer no protection against HPV — one of the most common STDs in America — which causes 90 percent of all cervical cancer. So even if you use them right every time, you’re still at risk for some STDs.