Can smoking cannabis over the years reduce semen quality?

Yes: Yes, smoking marijuana can reduce semen quality and overall fertility. Not only can sperm count be reduced, but the sperm's ability to attach to an egg is affected. There are cannabinoid receptors on sperm, which can make them swim abnormally when stimulated by thc. http://www.medicalnewstoday.com/releases/4482.php.

Absolutely!: Studies have shown that regular cannabis smokers have significantly less seminal fluid, and a lower sperm count. Their sperm are also more likely to swim too fast too early, leading to burn-out before they reach the egg. It is thus advisable that anyone trying to conceive should not smoke marijuana, and that would include women as well as men.