A growing number of Dr. Michael Eisenberg’s patients want to know: Is smoking pot a risk factor for erectile dysfunction or lower libido?
Eisenberg, a Stanford University urologist, didn’t have much to go on. Although an estimated 22 million people in the United States currently use marijuana, and 29 states and the District of Columbia have legalized the drug in some form, he could find little evidence in the scientific literature to answer that question.
“My own bias is I thought it would probably be like cigarette smoking, that there would be an inverse correlation,” Eisenberg told me. According to a 2016 review of the research, the more and longer men smoke cigarettes, the greater their risk of erectile dysfunction.
But experiments in animals and humans have shown that marijuana stimulates parts of the brain involved in sexual arousal and sexual activity. And a new population-based study coauthored by Eisenberg and Dr. Andrew Sun, a Stanford urology resident, found that marijuana users are having more sex, not less.
Eisenberg and Sun analyzed data collected in 2002 and 2006-2015 by the National Survey of Family Growth, a nationally representative cross-sectional survey. The data covered approximately 28,000 women and 23,000 men, ages 25 to 45, who had been asked whether they had used marijuana in the previous year, month or day. About 24.5% of the men and 14.5% of the women said they had.
It turns out that both male and female marijuana users had sexual intercourse more frequently, not less, than people who didn’t use pot. Specifically, women who said they used pot daily on average reported having sex 7.1 times in the previous four weeks, compared to 6.0 times for women who said they had never used pot in the previous year.
The difference was even greater in men, with daily pot users reporting having sex 6.9 times in the previous four weeks, compared to 5.6 times for men who had not used pot in the previous year. The association was independent of age, race and ethnicity, education, marital status and other demographic factors as well as cocaine and alcohol use.
The study appears in the November issue of the Journal of Sexual Medicine.
Before you jump to the conclusions that pot is an aphrodisiac and that medical marijuana could be used to treat erectile dysfunction (although that has been suggested), you should consider the study’s limitations.
For one, this is the first study to examine the connection between marijuana and the frequency of sexual intercourse in the U.S. population. As Eisenberg and Sun wrote, “additional research is needed to further define this association and address critical questions regarding marijuana use and sexual function.”
All of the data in their analysis were self-reported, so participants’ recall could be faulty or they might have exaggerated, Eisenberg and Sun noted. Plus, the survey data represented snapshots taken at a particular point in time, but marijuana use and sexual frequency could vary over time. And Eisenberg and Sun did not have information about how much pot survey respondents used or how frequently they used it in the previous week, month or year. Lastly, their study provides no information about the relationship between marijuana use and frequency of sexual activity in men older than 45. Increasing age is considered to be a risk factor for erectile dysfunction.
While marijuana use did not appear to be linked to erectile dysfunction in Eisenberg and Sun’s study, it might be associated with reduced male fertility, a 2015 Danish study suggested. That study assessed semen samples from 1,215 Danish men ages 18 to 28. Nearly half of them reported having smoked marijuana within the previous three months. Compared to those who said they hadn’t smoked any marijuana, the young men who said they smoked more than once a week had a 29% lower sperm concentration and a 28% lower sperm count.
The Danish study was one of the first to rigorously examine the connection between marijuana use and semen quality in the general population, Eisenberg wrote in a commentary on the research. Whether those findings would apply to U.S. men isn’t clear, because, as he noted, other research suggests that Danish men on average have a lower sperm concentration than men in other countries.
When patients ask about the relationship between smoking pot and their ability to get an erection, Eisenberg says, he’ll share his new data.
“It’s certainly reassuring that this is probably not the primary driver of erectile dysfunction in this population,” he said. Of course, he added, on the other hand, “if they were to stop smoking pot this wouldn’t necessarily turn things around.”