Can you get an STI while wearing a condom?

Written by

Lauren Dobischok
29 March, 2023

Medically checked article All HOMED-IQ content is reviewed by medical specialists

Condoms are a good way to prevent both sexually transmitted infections (STIs) and pregnancy. Transmission of most STIs can be prevented with condoms if they are used correctly and are not broken or expired. While many people believe that condoms are a foolproof way to prevent all STIs, there are certain STIs that condoms do not completely protect against. That is why getting tested for STIs regularly is important, even if you practice safe sex. This blog will summarize STIs that can be transmitted while using a condom, how to correctly use a condom, and other ways to reduce your risk for STIs.

What is a condom?

Condoms are thin barriers that prevent body fluids such as semen, vaginal fluids, and blood from exchanging between sex partners (CDC, 2021). While condoms can prevent pregnancy by stopping semen from entering the vagina, they also protect against STIs by stopping or greatly reducing the exchange of body fluids (genital fluids, blood, semen, or pre-cum) or skin-to-skin contact between the genitals. Condoms can be used during vaginal, anal, or oral sex to help prevent STI transmission.

What types of condoms are there?

There are two types of condoms: condoms used externally and condoms used internally. 

An external condom (sometimes called a male condom or condom) is worn over the penis during sex. They are made of latex, plastic, rubber, or natural membranes. Latex condoms provide good protection against pregnancy, HIV and other STIs. Plastic or rubber condoms are a good alternative for people who have a latex allergy, but may break more easily than latex condoms (Walsh et al., 2003). Natural membrane condoms can protect against pregnancy by stopping sperm, but do not protect against STIs (CDC, 2021). 

An internal condom (sometimes called a female condom) is placed inside the vagina or rectum during sex. When used correctly, they can protect against pregnancy and STIs (CDC, 2021). Internal condoms should not be used at the same time as external condoms to prevent tearing.

This article refers to external condoms made of latex, plastic, or rubber when discussing STI prevention. 

How can STI transmission or pregnancy occur if condoms are used? 

The reliability of a condom at preventing pregnancy depends on how it is used. When used properly, condoms are 98% effective (NHS, 2022). With real-world use, they are believed to be around 85% effective. They are not completely effective at preventing pregnancy because they sometimes slip off, tear, or break. If a condom breaks or comes off during sex, you may need emergency contraception or to get tested for STIs.

STIs are transmitted through exchange of body fluids or from skin-to-skin contact. Since condoms do not cover all of the skin and can break or slip off, they reduce the chance but do not completely eliminate the risk of STI transmission (NIH, 2021).

What STIs do condoms protect against? 

STIs transmitted via body fluids

When used correctly, condoms offer good protection against STIs transmitted via body fluids, such as chlamydia, gonorrhea, HIV, hepatitis B, and trichomoniasis. Laboratory studies have found that condoms form a barrier that prevents body fluids from being exchanged between sex partners (CDC, 2021).

STIs transmitted via skin-to-skin contact

Condoms can also protect against STIs that are transmitted via skin-to-skin contact, such as syphilis, genital herpes, and HPV. However, condoms can only protect against these STIs if the condom covers the area in which they occur. If they appear in areas in which a condom does not cover, it is possible for the STI to be transmitted even if condoms are used (NIH, 2021). 

For example, if an individual has a herpes outbreak on the shaft of the penis, condoms could cover and effectively protect against transmitting this STI to others. However, if the outbreak was located on the testicles or the skin at the base of the penis, condoms do not cover this area and the virus could be transmitted if skin-to-skin contact occurs with these areas.

What is the correct way to use a condom? 

It is important to use condoms correctly in order for them to be effective against STIs. Here are some tips on how to use a condom properly:

  • Use a condom every time you have sex, before contact between genitals occurs.
  • Use a new condom every time you change type of sexual activity (i.e. from vaginal to anal or oral sex). 
  • Do not reuse condoms or use more than one condom at once.
  • Use a condom that fits: a loose condom slips off more easily, while one that is too tight can break. 
  • Check the expiration date of condoms before use. Do not use expired condoms.
  • Use your fingers to open condom packages; opening the package with your teeth can damage the condom. 
  • Store your condoms in a cool, dry place. Do not keep them loose in your purse, bag or pocket. This can create friction that can damage the condoms. 
  • Do not use oil-based products with condoms (such as lotion, petroleum jelly, or other oil-based lubricants). Oil-based products can cause condoms to break down. Alternatively, use water or silicone-based lubricants.

Source: CDC, 2022

Other ways to reduce the risk of STIs

In addition to using a condom, there are other ways you can reduce your risk of contracting or transmitting an STI. 

Have a mutually monogamous sex partner or reduce your number of sex partners

Reducing your number of sex partners can decrease your risk of STIs (CDC, 2023). However, it is still important to get tested regularly and to practice safe sex if you have changing sex partners or a sex partner that has sex with more than one person. 

Practicing mutual monogamy, meaning you agree to have sex with one person who also agrees to only have sex with you, is one of the most reliable ways to avoid STIs (CDC, 2023). Having an honest conversation, getting tested beforehand, and sharing your test results with your partner is important to ensure you both do not have STIs.

Talk about sexual health

Communicating with your partner about their sexual health is another important aspect of STI prevention. It may be uncomfortable, but knowing your partner’s STI status, sexual history, and other sex partners can help you make informed decisions regarding sex. This is especially important in a new monogamous relationship or when you have alternating sex partners. Ask your partner about the last time they were tested for an STI and if they have had unprotected sex since that time. You can also ask if they are seeing other partners or to go get tested with you. One way to start the conversation is by first talking openly about your own sexual health. 

Understand the limits of STI testing

When discussing sexual health with your partner it is also important to understand which STIs can be detected with a blood test. At this time there is no male test for HPV, and many standard STI tests do not check for herpes unless visible blisters/lesions are present. Part of discussing sexual health with a partner should be learning what STIs they were tested for, whether they have ever had outbreaks of genital warts/herpes lesions, or whether they have had a female partner that had a confirmed case of HPV. 

Interested in testing for HPV? Try Homed-IQ’s HPV Test for Women.

It is also important to understand when a test can detect STIs. STIs can only be detected after the window period has passed. This is the time between when an individual was exposed to an STI and when a test can reliably detect it. If someone took an STI test following a potential exposure but before the window period had passed, there is still a risk they have an STI. Unsure about your past STI status? Getting tested is the most reliable way to check. 

Get tested regularly for STIs

If you have alternating bed partners or are planning to have unprotected sex with a new partner it is important to test for STIs. Homed-IQ’s STI Test Comprehensive gives you a comprehensive overview of your sexual health. Without visiting a doctor or clinic. You test for the 9 most common STIs, including chlamydia, HIV, herpes and gonorrhoea. This test involves taking a sample from home and mailing it to a certified laboratory for analysis. We also offer an HIV Test. Reliable results are available within days! Unsure of what STI(s) to test for? Try Homed-IQ’s STI Test Guide.

Do condoms protect against all STIs?

In short, condoms provide good protection against pregnancy and many STIs if they are used properly, but they aren’t perfect. By learning how to use condoms properly, getting tested regularly, and talking to your partner(s) about sexual health, you can ensure both you and your partners stay healthy and STI-free.


Centers for Disease Control. (2021a, May 13). Condoms | Prevention.,synthetic%20rubber%2C%20or%20natural%20membrane.

Centers for Disease Control. (2021b, September 14). Condom Fact Sheet In Brief | CDC.

Centers for Disease Control. (2022, February 10). How to Use a Male (External) Condom | CDC.

Centers for Disease Control. (2023, February 22). Prevention – STD Information from CDC.

NHS. (2023, January 9). Condoms.,clinics%20and%20some%20GP%20surgeries.

NIH. (2021, November 18). How can men reduce the risk of getting a sexually transmitted disease (STD)?

Walsh, T. L., Frezieres, R. G., Peacock, K., Nelson, A. L., Clark, V. A., & Bernstein, L. (2003). Evaluation of the efficacy of a nonlatex condom: results from a randomized, controlled clinical trial. Perspectives on sexual and reproductive health, 35(2), 79–86.

About the author

Lauren Dobischok

Lauren is a health scientist and science communicator currently living in the Netherlands. Originally from Canada, she completed a Research Master’s in Health Sciences at the Netherlands Institute of Health Sciences at Erasmus University Rotterdam (NIHES) with a specialisation in epidemiology. Prior to her master’s degree, she completed a Bachelor’s degree in Health Sciences at Simon Fraser University. With a background in public health, her goal is to create accurate scientific content that is easy to understand and empowers people to make informed decisions. Within Homed-IQ, Lauren works as a Product Developer and Content Lead, working closely with physicians and scientists on medical devices for Homed-IQ’s new products and written communications.