Person holding a half-unwrapped condom package with a pink condom sticking out of the wrapper.
Person holding a half-unwrapped condom package with a pink condom sticking out of the wrapper.

Condoms Unwrapped

When and How to Use Condoms

When used properly, condoms are effective at reducing risk of sexually transmitted infections (STIs) and the risk of pregnancy.

There are three different types of condoms:

1. External condoms are sheaths that go around a penis during sexual intercourse. To use an external condom:

  • Check the packaging to make sure it is not expired or damaged.
  • Remove the condom and roll it down an erect penis, leaving room at the top for semen by pinching the top as you roll it on.

2. Internal condoms are tubes inserted into the vagina or anus for protection during sexual intercourse. To use an internal condom:

  • Check the packaging to make sure it is not expired or damaged.
  • Use your fingers to insert the tube into your vagina or anus.
  • Wrap the remainder of the condom around the vulva and walls of the vagina, or anus, for additional protection.

3. Dental dams are thin square sheets made with latex or polyurethane. They are used as a barrier between the mouth and vagina or the mouth and anus. To use a dental dam:

  • Check the packaging to make sure it is not expired or damaged.
  • Place dental dam flat to cover vaginal opening or anus.
  • The dental dam should be large enough to cover the entire vaginal or anal area.
  • Hold the dental dam in place during oral sex. 

What Are Condoms Made Of?

  • Latex: Most condoms are made with latex. Latex is great in terms of protection against STIs, but some people have a latex sensitivity or allergy.
  • Lambskin: Lambskin condoms typically come lubricated, but they have small pores and therefore aren’t the best for preventing infection. These condoms can reduce the risk of pregnancy but they are not effective as protection from STIs.
  • Synthetic (polyisoprene, nitrile, polyurethane or polyethylene): The effectiveness of synthetic condoms against STIs has not been well studied. If you are concerned about STIs, a latex condom is the most effective option.


“It's important to know that you should not use a petroleum-based lubricant, such as Vaseline or baby oil. They are not latex condom compatible,” says Alexander L. Lin, MD, a gynecologist at Northwestern Medicine. “A water-or silicone-based lubricant certainly can be used, if desired, to improve the feeling.”

Condoms and Risk

Condoms can’t prevent 100% of STIs all of the time. Condoms are effective against STIs that are transmitted through genital fluid, such as chlamydia, gonorrhea and trichomoniasis. Condoms are less effective for STIs transmitted by skin-to-skin contact, such as genital human papillomavirus (HPV). The only way to have absolute protection from STIs is to not have any genital contact.

Timing is crucial for optimizing protection with condoms. Condoms are most effective if you use them at the first point of sexual contact, not just before penetration. Whenever there is intimate genital or genital-oral contact, you should use a condom to prevent herpes, HPV and STIs transmittable via skin-to-skin contact.

Internal and external condoms are effective at preventing pregnancy, as long as they are used at the start of genital contact and they do not break or leak. According to the Centers for Disease Control and Prevention (CDC), external condoms, sometimes called male condoms, have a 13% typical failure rate and internal condoms, sometimes called female condoms, have a 21% typical failure rate. In the event of unprotected intercourse, emergency contraception is effective and some types are available over the counter.

Condom Conversation

It’s important to have an open conversation with your sexual partners about how you’re going to protect each other from STIs and prevent pregnancy. Talk to your physician about contraception methods and STI prevention methods that will work with your lifestyle.

Although you might feel uncomfortable asking your physician about condoms, STIs or other topics related to sex, never hold back. “Patient education is as important as anything else that we do,” says Dr. Lin. “We are here to help you live your safest and healthiest life.”