Pot. Weed. Marijuana. Whatever you call it, smoking the funny stuff may up your odds of testicular cancer.  Here’s what all of you recreational users need to know about the risks.

Rising testicular cancer rates in the last three decades prompted researchers from the University of Southern California to investigate whether or not there was a link between recreational drug use, the environment, and this type of cancer. The study, published online in CANCER, included 163 men who were diagnosed with testicular germ-cell tumors and 292 healthy men. Both sets of men were matched according to age, race and neighborhood. Each participant answered questions about their drug use and provided family history of cancers, personal disease history, and use of tobacco, alcohol, and recreation drugs. 

A two-fold increased risk was found among frequent pot smokers (more than once per week for 10 or more years) when compared with those who never or rarely used the drug (less than once per week for less than 10 years). Specifically, researchers found a link between recreational use of marijuana and an increased risk of developing nonseminoma and mixed germ-cell tumors, which lead to a somewhat worse prognosis. The malignant nonseminoma and mixed germ-cell tumors are more likely to affect men ages 15 to 30 and (maybe not) coincidentally, pot use among guys ages 15 to 20 has increased in recent years. 

One explanation for the increased risk of testicular tumors in young guys may be that marijuana smoke may cause testicular carcinogenesis. That’s because the main ingredient in pot that interacts with your body affects the endocannabinoid system (which is linked to your hormones). The endocannabinoid receptors get disrupted, and they’re in charge of maturing sperm. In a nutshell: less sperm production, less testosterone, and worse health for your boys. 

If you’re worried about testicular cancer (or low sperm count), it’s probably best to skip the pot.