Dr. Michael Eisenberg, an assistant professor of urology, sees a lot of patients at the Stanford University Medical Center who have problems performing in the bedroom.
To determine what the problem is, they’ll go through a laundry list of regular activities. Often, patients will ask whether they need to smoke less marijuana.
There isn’t a lot of research on the topic. However, with marijuana becoming legal in a growing number of states, Eisenberg thought it’d be worth exploring. What he found surprised him.
“Usually, people assume the more frequently you smoke, the worse it could be when it came to sex, but in fact, we learned the opposite was true,” Eisenberg said. His study was published in this week’s Journal of Sexual Medicine.
The study looked at data from the US government’s National Survey of Family Growth. It asked more than 28,000 women and nearly 23,000 men how often they had sex in the four weeks prior to the survey and how frequently they used marijuana in the past year.
Women who didn’t use marijuana reported having sex six times on average during the past four weeks. Women who used marijuana daily had sex 7.1 times on average.
The trend was similar for men. Men who abstained from marijuana said they had sex an average of 5.6 times in the four weeks before the survey, compared with the daily marijuana users who reported having sex 6.9 times, on average.
“We were surprised to see the positive association between users,” Eisenberg said. “This was across the board: marital status, race, none of that mattered.” The study focused on heterosexual sex, and it didn’t explain why there might be a connection between sex and marijuana.
Eisenberg said past research on human and rodent models has shown that marijuana use may generally increase arousal. However, studies have also shown that too much marijuana use can decrease sperm count, and while men may want to have sex more, orgasm may be a challenge.
“It can have a different impact on different people,” said Joseph Palamar, an associate professor in the Department of Population Health at New York University, who is not connected with the current study.
He thought it was a “cool epidemiological paper” that “did the best it could with the data,” but it did have limitations. “It’s unclear from the data if people had marijuana in their system before or during sex,” Palamar said. Someone could smoke in the morning but not have sex until the evening, when it wouldn’t be in their system any more, for example. He added he’d like to see a study that could show more of a direct effect on frequency.