Legalising Medical Marijuana May Boost Sexual Activity, Study Finds

In a potentially uplifting finding for millennials, a new study suggests that young adults aged 20 to 30 living in states with legal medical marijuana are more likely to engage in sex — and may even experience higher birth rates.

Published in the Journal of Health Economics, the research is one of the first to focus specifically on medical marijuana laws (MMLs) and their impact on sexual behavior and fertility.

Previous studies had shown that daily cannabis users tend to have 20% more sex than non-users. But this latest study, conducted by researchers from the University of Connecticut, dives deeper by linking the implementation of medical marijuana laws between 2005 and 2014 to changes in sexual frequency, contraceptive use, and birth rates among young adults.

Using a differences-in-differences approach — a statistical method that leverages the staggered rollout of laws across states — the researchers uncovered a clear pattern:

• Sexual activity increased after the legalization of medical marijuana.

• Contraceptive use decreased, but only among those who were sexually active.

• Birth counts rose, suggesting that cannabis may be influencing reproductive outcomes through behavior rather than biology.

Interestingly, there was also a temporary uptick in gonorrhea rates, hinting at broader public health implications.

The researchers believe the changes stem from marijuana’s influence on behavior and risk perception — boosting immediate pleasure-seeking (hedonic) behaviors while dulling concerns about future consequences.

While marijuana is known to have physiological effects that could reduce fertility, the findings suggest these may be outweighed by increased sexual frequency and reduced contraceptive use in states with medical cannabis access.

In short, legal access to medical marijuana might be making sex more frequent, less protected, and — at least in some cases — more fruitful.