Sexpert: April 14, 2011

Dear Sexpert,

Whenever my roommate has sex the room ends up smelling really bad. What is up with my friends’ body chemistry and what can they do about it?

— Olfactorily Perturbed

Dear Perturbed,

It is important to note that there is a host of causes of sex-related smells. Any or none of those that I mention may be applicable to your roommate and his or her sexual partner(s), so keep that in mind as you consider approaching your roommate with this problem.

First, there are several completely natural causes for odors after sex; some even are not explicitly sexual. Because sex is a physically demanding act that greatly increases heart rate and blood flow, people will often perspire quite a bit. This large amount of perspiration in a confined space is likely to cause a smell. Sexually, vaginal fluid and semen are both natural, and in many cases unavoidable, outcomes of sex and will likely add to the already sweat-soaked stench.

However, a bad smell can also be a symptom of a variety of issues that may indicate some kind of abnormality. There are several STIs that can cause malodorous discharge, including genital warts and gonorrhea. Also, a common culprit of smell among women is bacterial vaginosis, a condition caused by an imbalance of bacteria in the vagina. Though not explicitly an STI because the bacteria occurs naturally in healthy women, it is often thought to be exacerbated by sex and may result in a fishy smell.

Though a woman who experiences this or other such conditions (such as a yeast infection) may eliminate odor later by showering after sex or even a change in diet (there is some evidence that eating yogurt with the bacteria L. acidophilus helps get rid of a yeast infection), little can be done for odors immediately after sex. The notable exceptions are STIs that might be causing the bad smell. Regular readers of my column will not be surprised that I suggest your roommate should consider going to McCosh to get tested for STIs if he or she suspects such a problem.

— The Sexpert

The Sexpert is written by a team of peer sexual health educators and fact-checked by University health professionals. Submit questions to sexpert@dailyprincetonian.com. Don’t be shy!