While cannabis has been shown to help enhance one’s sex life, the question remains about the efficacy of cannabis for those trying to conceive. A newly released study published by the Canadian Medical Association Journal highlighted four key findings about the impact of cannabis use on fertility.
- Tetrahydrocannabinol (THC) acts on the endocannabinoid system, which is ubiquitous in reproductive tissues. THC activates the cannabinoid receptors, which are part of the endogenous endocannabinoid system found in the hypothalamus, pituitary, and internal reproductive organs in men and women.
- Marijuana use can decrease sperm count. Those men who smoked cannabis more than once a week in the proceeding three months had a 29% reduction in their sperm count.
- Marijuana use may delay or inhibit ovulation. On average ovulation was delayed by 1.7 to 3.5 days among those women who smoked cannabis more than three times in the three months before the study.
- For couples with subfertility or infertility, the changes in sperm count and ovulation caused by smoking cannabis could make it more difficult for them to conceive. However, fore those couples who did not have infertility issues, smoking cannabis did not significantly affect time to pregnancy.
Furthermore, some scientists suggest the effects of marijuana on fertility appear to accumulate over time. This means that by the time a chronic marijuana smoking woman is in her mid-20s, she might be more likely to experience a delay in getting pregnant.
Other studies seem to dispute at least some of these findings. For example, a 2018 study conducted by Boston University School of Public Health researchers and published in the Journal of Epidemiology and Community Health (JECH) surveyed over
4,000 women and 1,125 of their male partners. This study concluded that cannabis use by men and women does not appear to lower a couple’s chances of conceiving.
Also, research led by the Harvard T.H. Chan School of Public Health indicated that men who have smoked cannabis at some point in their life had significantly higher concentrations of sperm when compared with men who have never smoked cannabis.
According to Feiby Nassan, lead author of the study and a postdoctoral research fellow at Harvard Chan School, these findings are consistent with two different interpretations. “The first being that low levels of marijuana use could benefit sperm production because of its effect on the endocannabinoid system, which is known to play a role in fertility, but those benefits are lost with higher levels of marijuana consumption. Nassan also stated, “An equally plausible interpretation is that our findings could reflect the fact that men with higher testosterone levels are more likely to engage in risk-seeking behaviors, including smoking marijuana.”
What these studies indicate is that additional research is needed on the effects of cannabis on fertility. Presently, there are few human studies on cannabis and fertility. Furthermore, self-reported studies are not reliable due to the illegal nature of cannabis in many states and countries, as well as the inability to provide quality control.