At the very least, a study published Friday in the Journal of Sexual Medicine suggests that people who smoke more weed are having more sex than those who smoke less or abstain. But whether it's cause or effect, isn't clear.
The researchers pulled together data from roughly 50,000 people who participated in an annual Centers for Disease Control and Prevention survey during various years between 2002 and 2015. "We reported how often they smoke – monthly, weekly or daily – and how many times they've had sex in the last month," says Dr. Michael Eisenberg, a urologist at Stanford University Medical Center and the senior author on the study. "What we found was compared to never-users, those who reported daily use had about 20 percent more sex. So over the course of a year, they're having sex maybe 20 more times."
When the researchers considered other potentially confounding factors, such as alcohol or cocaine use, age, religion, having children, the association between more marijuana and more sex held, Eisenberg says. "It was pretty much every group we studied, this pattern persisted," he says. The more marijuana people smoked, the more they seemed to be having sex.
Now, that association doesn't necessarily mean the weed is responsible for the heightened sex drive, says Mitch Earleywine, a psychologist at the University at Albany who has studied cannabis and sex but wasn't involved in this work. "In some surveys, we saw that people [who used cannabis] did have sex more, but it seemed to be mediated by this personality type that's willing to try new things or look for thrills," he says. In other words, it seems that people who like to smoke weed may have other character traits that lead them to be lustier.
Or maybe it really is the weed. "It's possible it makes men or women more interested in sex," Eisenberg says. In one study, researchers found they were able to induce sexual behavior by injecting a cannabinoid, the class of psychoactive compounds in marijuana, into rats. But people aren't rats, of course.
Another study published in 2012 found that women became more aroused when watching erotic films when they had cannabinoids in their system. But that might just be because weed seems to heighten sensory experiences overall. "It gets people to appreciate the moment more anyway," psychologist Earleywine says. "They like food more, find humor in things more easily, so it wouldn't be stunning to think they would enjoy sex more."
Whatever the connection, Eisenberg says his results leads him to think that pot, unlike tobacco which can depress libido and performance , isn't going to take the steam out of one's sex drive. "One question my patients always have is will smoking marijuana frequently negatively impact my sexual function?" Eisenberg says. "We don't want people to smoke to improve sexual function, but it probably doesn't hurt things."
Not everyone agrees with that conclusion. "It's a lot of stretch here," says Dr. Rany Shamloul, a researcher at Ottawa Hospital in Canada who focuses on sexual health and function. He didn't work on the latest study. In an odd Catch-22, Shamloul says that recent research suggests cannabis might actually make it harder for a man's penis to become erect, even if weed might turn people on. "Recent studies have shown cannabinoid receptors in the penis itself, and experiments in the lab show an inhibitory response," he says. "There was basically a mixed result. Cannabis might increase [sexual arousal] frequency in the brain, but also decrease erectile function in the penis."
There's another issue that may throw cold water on cannabis' potential as a love enabler. A frequent side effect of marijuana is a dry mouth, and University at Albany's Earleywine points out that one's mouth might not be the only thing turning arid. "Drying of the mucus membranes is a pretty consistent effect of the plant. Women should keep that in mind when considering cannabis as a sexual aid. I know that some products have THC or cannabinoids in a lubricant, but I haven't seen any actual data on that," he says.
Stanford's Eisenberg says his study doesn't prove the idea that marijuana is getting people into the sack, though he says that's a possibility. There's really only one conclusion he can safely draw from the work: cannabis users are doing it more.