Bookmark and Share Subscribe
San Francisco City Clinic Search
Ask Dr. K

I recently had unprotected sex, both top and bottom with another guy, who tricked me into believing he was using a condom. Immediately after sex I excreted in the toilet and used Listerine to wash myself out. I have not experienced any flu-like symptoms. What are the chances of contracting HIV?

First of all, the idea that washing with Listerine can prevent STDs is a myth. Washing after sex will not hurt you, but using antiseptics like Listerine will not help prevent STDs or HIV. The sure-fire way to lessen risk is to use a condom during sex.

Also, just because you have not experienced flu-like symptoms does not mean you are HIV or STD free. Many people do not show any symptoms when they are infected, so it is possible to have gotten infected and not know it.

It is impossible to tell you what the chances are that you contracted HIV, especially since we do not know if your partner was HIV positive. But we do know that unprotected anal sex puts you at risk for many different STDs, including chlamydia, gonorrhea, herpes, HIV, and syphilis. And being the bottom elevates your HIV risk.

What you need to do now is get tested! Learn your HIV status. We’d recommend using the most advance HIV testing protocol which would include an HIV RNA test—a special test that finds very small amounts of virus in the blood. If you cannot get an HIV RNA test with your antibody test, be sure the antibody test uses blood and not just the saliva. The saliva HIV tests are just not that accurate in your situation.

To learn more about HIV, visit For more information on STD testing, visit City Clinic for information about getting tested in San Francisco or call the CDC National Hotline for services near you: 1-800-CDC-INFO.

To your health,
Dr. K

Last modified on Thursday, November 19, 2009.
Privacy Policy | Photo Disclaimer | Feedback
©2019 Department of Public Health, City & County of San Francisco.