Ask the Doctors

Dear Doctor: Do marijuana users really have more sex? Why would that be? I ask out of simple curiosity, of course.

Dear Reader: I suspect you're referring to a recent, much-publicized study in the Journal of Sexual Medicine. Before I answer your question, however, let's consider: Why is sex so important? From a biological perspective, male-female sex is necessary for procreation and, without it, none of us would be here. But aside from the sperm-meets-egg function of intercourse, greater amounts of sex with one partner have indeed been linked to greater happiness.

A 2015 study in the journal Social Psychology and Personality Science analyzed data from three studies totaling more than 30,000 people. The study looked at sex frequency, relationship satisfaction and happiness. The authors found that, although sexual frequency led to greater relationship satisfaction and happiness, those factors plateaued when sex occurred four to six times per month -- meaning that having sex more than once a week did not alter relationship satisfaction or happiness compared to having intercourse once a week.

This brings us to the latest study in the Journal of Sexual Medicine. The authors analyzed data from a health questionnaire called the National Survey of Family Growth. Participants ages 15 to 44 were asked about their frequency of intercourse four weeks prior to the survey. The participants also were asked about their frequency of marijuana use; 28,176 women and 22,943 men participated in the study, with an average age of about 30.

Granted, the study's parameters were narrow, featuring only questions about male-female sex. Still, marijuana use did correlate with higher sexual frequency. In a four-week time period, men who had never used marijuana had sex an average of a little more than five times; men who used marijuana weekly had intercourse an average of six times; and men who used marijuana daily had sex an average of seven times. Among women, those who had never used marijuana had intercourse an average of six times, while those who used it weekly or daily had intercourse an average of seven times.

Keep in mind, however, that the link between marijuana and sex is a correlation -- it doesn't reflect causation. The true connection between the two may simply be risky behavior. That said, for many people, marijuana is a relaxant, helping them forget their anxieties. It also decreases inhibition, and many users report that sexual experiences are more pleasurable with the drug. So it's simple to deduce how marijuana could increase sexual frequency.

Regardless, an increase in sexual frequency of one to 1 1/2 sex events per month hardly seems enough to warrant regular marijuana use. It certainly seems unlikely to increase the happiness we referenced earlier.

For starters, users can become dependent upon the drug, needing it before they have sex. Also, marijuana, like alcohol and other drugs, can lead to more promiscuous behavior, especially in younger adults. This can lead to intercourse with multiple partners and a failure to use condoms, raising the risk of sexually transmitted diseases.

So yes, marijuana use may lead to slightly more sex -- but also more risk.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

More like Ask the Doctors