Men who use marijuana may want to think twice if they hope to be fathers someday. New research from the Tulane University suggests that smoking marijuana may be harmful to male fertility. In the study of 409 men, 71 reported ongoing marijuana use while 103 reported past marijuana use. Compared to those who were not users, current and past users were twice as likely to have low semen volume and abnormal sperm development, even after adjusting for other lifestyle and behavioral factors. Both low semen volume and abnormal development can make it much harder to conceive a child. The researchers did acknowledge in the study that it is unknown if the changes due to marijuana use are reversible or how long recovery may take following cessation of use.

Dr. Sharif Mohr, epidemiologist with Drug Free America Foundation remarked, “We know from other research that average testosterone levels and sperm counts have been on the decline for several decades in the US, so I would expect this problem to accelerate as use of marijuana becomes increasingly common. What I find particularly concerning is the ability of THC to alter the genetic profile of sperm, which may adversely impact future progeny. Yet another reason to stay away from marijuana—as if another was needed!”

Source: Hehemann MC, Raheem OA, Rajanahally S, Holt S, Chen T, Fustok JN, Song K, Rylander H, Chow E, Ostrowski KA, Muller CH, Walsh TJ. Evaluation of the impact of marijuana use on semen quality: a prospective analysis. Ther Adv Urol. 2021 Jul 20;13:17562872211032484.