Gentlemen, if you like to party and also plan to have kids one day, we’ve got some bad news for you.

Men produce literally millions of sperm a day, but it is still common for a healthy man with a fertile partner to take a year to conceive.

But there is solid evidence that drug use can seriously disadvantage your little swimmers — and damage your chances of starting a family.

Some studies are more conclusive than others and, often they only examine heavy drug users, but it still makes for some sobering reading.

Guard your loins, gents. This is what drugs do to your sperm.



Some argue that marijuana should be legal, but what does the drug do to your sperm count? Source: News Corp Australia


It is typically seen as the least harmful of illicit drugs, but cannabis can pretty much turn your little swimmers into burnouts.

Tetrahydrocannabinol (THC), the active ingredient in marijuana, decreases sperm production and weakens sexual drive by interfering with the production of testosterone.

US reproductive expert Ricardo Yazigi told Vice that 33 per cent of chronic users had low sperm counts.

He said the active components in the drug were synthesised by the body, which actually made sperm less active.

“Binding of the active components and metabolites of marijuana to receptors on sperm themselves has also been shown to lead to decreasing motility rates,” Dr Yazigi said, which means the drug impairs the sperm’s ability to move properly through the female reproductive tract and fertilise an egg.

There is less evidence about how those who might have an occasional joint or two are affected.

“No good studies have been done but the prevailing thought is that while these men will have rapid recovery to their sperm function with briefer … use, they should avoid use when trying to get pregnant as well,” Dr Yazigi said.

Fertility treatment expert Amin Gafar says people who had used cannabis recently should wait a month before tyring to conceive.


Careful there buddy. Overdo it, and you could be in trouble.

Well, this is a relief. Light to moderate drinking does not appear to affect male fertility.

alcohol_retail_in_australia_2But it’s not such a rosy picture for heavy drinkers. Too much alcohol can decrease testosterone and actually increase a man’s oestrogen, which is women’s primary sex hormone. All of this is bad news for sperm production.

However, the harmful effects can be reversed if you cut back on the beers.

The National Health and Medical Research Council recommends men and women drink no more than four standard drinks on a single occasion to avoid health effects.


Cocaine and baby-making don’t mix.

Cocaine can lead to erectile dysfunction because the drug narrows the blood vessels, a process known as vasoconstriction.

But studies on the effects of cocaine by itself are limited because users tend to use cocaine with a cocktail of other drugs.



“Most of the time there’s coexistence of the use of cocaine along with alcohol and cigarettes and other drugs, so the single cocaine users are almost a rarity,” Dr Yazigi told Vice.

Animal studies have concluded that there are receptors for coke in the testicles and sperm, and the drug can degenerate the testicular tissue.

Some trials even found that cocaine could be transferred from the sperm to the female egg, which can lead to early miscarriage.


Long-term use of this class of drugs, which includes heroin, OxyContin and vicodin, can damage the male reproductive system because it suppresses the hormone GnNH, which is normally secreted by the organ that controls the pituitary gland.

This leads to a decline in the hormones needed to create sperm.
There also evidence that opiates can fragment DNA within sperm, leading to lower fertilisation rates and miscarriage.



Meth, aka ice, is one of the most insidious drugs and, while sperm count may not be top of mind for users, it does have a direct effect on fertility.

The drug can damage men’s seminiferous tubules, the place where sperm germinates, matures and transports in the testes.

Drug expert Fernando Caudevilla told Vice that the main problem with these drugs was the risk of heart deformity in children.


Ecstasy can affect the production of the hormone testosterone.

There isn’t much conclusive research, but ecstasy can damage the production of testosterone, damage sperm DNA, degenerate testicle tissue and reduced sperm count.

Like meth, there is also the danger that MDMA can cause heart problems in children.


Steroids can damage the normal function of the testes. Source: News Corp Australia

The abuse of anabolic steroids can lead to secondary hypogonadotropic hypogonadism, which is essentially the diminished function of the testes.

The drugs, popular with professional body builders and recreational power athletes, are used to build muscle mass, and can interfere with the hormone signals that are needed to produce sperm, according to the Cleveland Clinic.

LSD (acid)

Studies are limited but if you’re on acid and keen to reproduce, there is no conclusive evidence that the drug affects sperm. Shagadelic.

The Bottom Line

The good news is that if you manage to kick your habit, you can return to normal sperm production.

Dr Yazigi said it takes about three weeks to clear affected sperm from your system and normal spermatogenesis (sperm production) will return in three to six months. For some men, however, it may take a few years.