Cannabis and Infertility - is there a link?

To chill or not to chill?

Cannabis, has been legalized in many parts of the world for medicinal and recreational use and more states are passing legislation in the US every year. However, as its usage becomes more widespread, questions about its potential impact on reproductive health are emerging. Research in this area is limited, but there is evidence to suggest that marijuana use may have negative effects on both male and female reproductive health. (And it has nothing to do with the oh so healthy high carb munchies). Is it me or does it feel like the fun police are making this journey even more stressful?

Most experts agree that smoking anything isn’t good for us. That’s because it creates toxins that cause oxidative stress (cellular stress), which negatively impacts the quality of health of the sperm and egg health. Most research is on smoking cannabis - but what about vaping, oils or edibles? Are they safer? How much is too much? We just don’t know yet but this is a big research area so watch this space.

Male Reproductive Health:

Some studies suggest that marijuana use can mess with male reproductive health in a few different ways. One Danish study found that men who smoked marijuana more than once per week had a 28% lower sperm concentration and 29% lower total sperm count compared to men who did not use marijuana. Another study conducted in the United States found that men who smoked marijuana had lower levels of testosterone, which is important for the production of sperm. Additionally, marijuana use has been linked to an increased risk of erectile dysfunction and decreased libido. In another study of 409 young male patients seeking an infertility evaluation, researchers found that a certain part of the marijuana compound (CBD) had affinity to latch or bind to receptors on the sperm’s structure, altering its shape and function, which can ultimately decrease fertility in men. Interestingly, the negative impact on sperm function was seen in both current and past marijuana users. But researchers don’t know how long men need to stop using marijuana — a week? a month? — to ge the ‘boys’ back to normal. Like much of new research - we need larger, methodologically sound studies. Weirdly enough researchers found it could improve sperm motility or how fast they can swim. Sperm motility was more likely to be lower in non-smokers than current and past smokers.

Female Reproductive Health:

The effects of marijuana on female reproductive health are less clear, but there is evidence to suggest that it may negatively impact fertility. Another Danish study found that women who used marijuana regularly had a 30% higher risk of infertility compared to women who did not use marijuana. Additionally, marijuana use during pregnancy has been associated with an increased risk of preterm birth and low birth weight. A 2023 study led by the University of California, Irvine (UCI), found adolescent female mice exposed to tetrahydrocannabinol (THC), the psychoactive chemical in the drug, had 50 percent fewer healthy ovarian follicles than the control group by the time they were adults. However a large study 2018 from Boston the PRESTO study was the first to evaluate the link between fecundability—the average per-cycle probability of conception—and marijuana use and found no difference. Some studies suggest links between implantation issues and even miscarriage - but you’ll also find studies that demonstrate no links.

How does cannabis impact fertility?:

The exact mechanisms by which marijuana affects reproductive health are not well understood. However, it is thought that the active ingredient in marijuana, THC, may disrupt the endocannabinoid system, which plays a key role in regulating fertility. THC may also affect the levels of sex hormones such as testosterone and estrogen, which are important for reproductive health. However CBD seems also to be involved in male fertility problems.

In a nutshell limited research available suggests that despite its stress relieving properties marijuana use may have negative effects on both male and female reproductive health.