If you and your partner are trying to get pregnant, it looks like cutting out marijuana is probably a good idea.
We recently did a story looking at the ways women's reproductive ability is affected by cannabis consumption Here are four ways you likely didn't realize cannabis can effect a man's reproductive health.
1. Reduced testosterone
Sounds like a Drug War-era scare tactic, but the "marijuana gives you man boobs" rumour may actually be true. "Marijuana affects a variety of hormones that are regulated by hypothalamic function," according to a 1983 study published by the National Institute on Drug Abuse, "and it appears that the psychoactive ingredient, THC, is the major compound responsible for this action." In animal studies, long-term exposure to marijuana altered the function of male reproductive organs; however, the same study found the effects were "completely reversible with time," and and "there is reason to believe that tolerance develops to these effects with acute exposure to THC."
2. Less active sperm
Turns out that smoking cannabis can send your little swimmers into a self-destructive state of overdrive. "Studies show that smoking pot has a detrimental effect on the way sperm behave, according to Advanced Fertility Services. "In a normal situation, the sperm enter a state of hyperactivation when they near the egg, giving them the final "push" needed to reach and fertilize the egg. But when you smoke pot, the sperm are hyperactive at the moment of ejaculation, causing them to essentially exhaust themselves before they are able to reach and fertilize the egg."
3. Lower sperm count
File this one under "possibly true": a mid-1970s study of testosterone levels in "chronic" cannabis users found that six of 17 subjects had oligospermia (low sperm count), and that average testosterone levels among cannabis users were just over half that of the control group. While that's mildly distressing, those findings weren't replicated in subsequent studies, indicating that the relationship between THC and sperm count isn't yet well-understood.
4. Erectile Dysfunction
Some studies conducted in animals have indicated that cannabis inhibits erectile function; however, there hasn't yet been enough research to determine whether this is also true in humans. It's worth noting that other studies have provided contradicted these findings, with some even "outline[ing] the beneficial effects of cannabis in enhancing erectile function" according to the 2011 study, "Impact of Cannabis Use on Male Sexual Health." It seems the your individual mileage may vary; however, if you can't get it up, getting pregnant's gonna be a little more tricky.
Since THC can be stored in the body for as long as a month, regular cannabis consumers - especially those who regularly roll Euro-style spliffs using tobacco - should take at least a month off if they're trying to conceive.