Leaders in Pharmaceutical Business Intelligence (LPBI) Group

Reporter and Curator: Dr. Sudipta Saha, Ph.D.

Research about marijuana and fertility is limited but some previous studies suggested that it might harm semen quality. Smoking of any type is also known to be a risk factor for male infertility. So, men who have smoked cannabis are expected to have worse measures of fertility but the data from a recent study suggested the opposite. The finding contradicts all conventional knowledge on how weed affects sperm. This may be because previous research typically focused on men with drug abuse history but this present study simply asked men if they had smoked more than two joints in their life.

Analysis of 1,143 semen samples from 662 men collected between 2000 and 2017 at the Fertility Clinic at Massachusetts General Hospital showed that those who had smoked weed at some point in their life had a mean sperm concentration of 62.7 million sperm per milliliter (mL) of ejaculate, while men who avoided marijuana entirely had mean concentrations of 45.4 million/mL. Added to this only 5% of weed smokers had sperm concentrations below the 15 million/mL threshold the World Health Organization has set for a “normal” sperm count, versus 12% of men who never smoked marijuana.

The study has some imperfections such as the participants are not necessarily representative of the general population. They were predominantly college educated men with a mean age of 36, and were all seeking treatment at a fertility center. Further research is needed to support the findings. Two possibilities are put forward by the researchers as the reason behind such data. The first is that low levels of marijuana could have a positive effect on the endocannabinoid system, the neurotransmitters in the nervous system that bind to cannabinoid receptors, and are known to regulate fertility. The second is that may be weed-smokers are just bigger risk takers and men with higher testosterone levels and thus have better sperm count.

But, there’s certainly no medical recommendation to smoke weed as a fertility treatment but this study, at least, suggests that a little marijuana doesn’t hurt and might benefit sperm production in some way. But, the researchers specified that their finding does not necessarily mean that smoking cannabis increases the chances of fatherhood.

References:

https://www.ncbi.nlm.nih.gov/pubmed/30726923

https://www.bloomberg.com/amp/news/articles/2019-02-06/cannabis-smoking-associated-with-higher-sperm-count-study-finds?__twitter_impression=true

https://qz.com/1543564/smoking-weed-linked-to-higher-sperm-count-in-a-harvard-study/

https://www.thestar.com.my/news/world/2019/02/06/cannabis-smoking-associated-with-higher-sperm-count-study-finds/

http://time.com/5520421/smoking-marijuana-sperm-fertility/

https://www.health.com/infertility/marijuana-sperm-count