How Long Can Sperm Live Outside The Body? This Viral Tweet Has Everyone Wondering

As anyone in a pregnancy scare has probably wanted to know, errant sperm can live inside the body for three to five days—provided the cells are in a warm, protective environment, like the uterus or cervix. But what about inside the mouth? Twitter user @_MariahV_ answered the question of oral sperm lifespan that most of us never knew we had:

Men’s Health attempted to contact Mariah via Twitter, and at publication time received no response, so sadly we can’t verify whether this hilarious thread is true. In it, she describes how a swab of a medical school classmate’s mouth showed that sperm was living inside her oral cavity. According to Mariah’s professor, this wasn’t the first time a discovery of this kind had been made, either. (However, it’s worth noting that a nearly identical story has been circulated as an urban legend over the years.)

In the interest of providing sound medical advice on whether the story could be true, though, we reached out to Brian Steixner, M.D., a urologist, and director of the Institute of Men’s Health at Jersey Urology Group.
“It’s interesting to think about,” Steixner says. “The important point is that most sperm will die pretty rapidly if they’re not in an environment that’s conducive to living. Sperm outside the body, on the coffee table, or wherever you decide to put them, they’re only going to live about 15 to 30 minutes.”

However, Steixner notes that hypothetically, the properties of the mouth could be conducive to harboring live sperm cells.

“If you’re talking about the science behind it, the temperature of the mouth is warmer than outside the body, it’s a mucosal substance with gums, nooks, and crannies,” Steixner says. “In theory, it’s 100 percent reasonable that a sperm from oral sex in someone’s mouth could be alive the day after, assuming it’s Monday, or two days later.” Steiner also notes that such a situation is highly improbable, but concedes that yes, the remnants of Saturday oral sex could stay with a person until Tuesday.

So, although male sperm counts are declining, be aware that sperm can live in other areas of your partner longer than you might think.