Marijuana Damages Sperm?


Smoking marijuana might damage sperm in more ways than one, according to two new studies. Marijuana can change the size, shape and quality of men’s sperm, which may impact his fertility. It can also have an impact on the way they swim.

In one study, published by the medical journal Human Reproduction, researchers examined several different lifestyle factors that could possibly have an impact on male infertility.  They studied how habits such as smoking cigarettes and/or marijuana and drinking alcohol affected men’s sperm size and shape.

Researchers studied 1,970 men who answered questions regarding their lifestyle and medical history at one of 14 fertility clinics. According to one of the researchers, 318 men in the group had sperm that was characterized abnormal; less than four percent of their sperm was the correct shape and size.

The goal of study was to define the highest risks of human fertility, according to Dr. Allan Pacey, a senior lecturer at the University of Sheffield in England. “Our data suggests that cannabis users might be advised to stop using the drug if they are planning to try to start a family,” he said.

The researchers compared the information from the men who donated the abnormal the rest of the study participants. Lifestyle choices and the time of year at which sperm was collected had an effect on sperm. They found that samples collected during summer months were nearly twice as likely to be considered abnormal. Cigarettes and alcohol were not shown to damage sperm, but, the study revealed that the size and shape of their sperm was negatively affected when the men had smoked marijuana within three months and were younger than age 30.

A separate study conducted by Scientists at Buffalo University, discovered that men who frequently smoked marijuana had a considerably lower sperm count and considerably less seminal fluid. Their sperm also had higher chances of swimming too fast too soon, causing them to burn-out before they reached the egg.

Scientists tested sperm samples of 22 men. The subjects smoked marijuana on average 14 times a week for a period of at least five years. They analyzed the sperm to find out when they began to swim very vigorously.

It is crucial that a sperm begins swimming vigorously as it nears the egg to improve it’s chance of successfully fertilizing it. However, chances of reaching the egg are significantly decreased if it swims too fast too soon, leading to infertility. “The sperm from marijuana smokers were moving too fast too early,” said Dr. Lani Burkman, the lead researcher on the study.

A number of chemicals known to affect human physiology are found in Marijuana, including tetrahydrocannabinol (THC). Scientists believe THC may impact the way sperm swim, or it may block mechanisms designed to remove malfunctioning sperm.

THC and other cannabis-related chemicals, have been shown to stimulate human sperm receptors. During the study, the sperm subjected to high levels of THC began swimming abnormally and lost the ability to attach to the egg, so that fertilization could take place.

The study did not examine whether the men’s sperm would return to normal after men stopped smoking marijuana. However, Burkman said men who have borderline fertility could tip the scales into infertility by smoking marijuana.

Both studies concluded that men who smoked marijuana had a much higher rate of damaged sperm than men who did not. Marijuana smoking contributes to higher rate of infertility in men.

By Brandi M. Fleeks

Medical News Today
Fox News

8 Responses to "Marijuana Damages Sperm?"

  1. Sandy Lender   June 15, 2014 at 4:11 pm

    I think if you are going to print a “news” article about a study, maybe you should use the actual study and not other “news” links for information & backup.

  2. Curtis Creek   June 15, 2014 at 1:03 pm

    Aaaaand….that’s a sufficient reason to continue to imprison people for using it? Because they’re not totally sure, but it SEEMS that it MIGHT have an impact on sperm?
    Just anectodally, it doesn’t seem to impact fertility in any meaningful way, just look at the Marley family.

  3. rickdday   June 15, 2014 at 8:06 am

    OH DEAR GOD JESUS NO! This is the LAST thing we should be telling our kids. Not only will it lead more teens to experiment, they will think that cannabis is a BIRTH CONTROL drug.

    Totally irresponsible on the part of NIDA, et al, for suggesting it’s OK to smoke pot and have unprotected sex.

    Think of the children~

  4. Malcolm Kyle   June 15, 2014 at 7:02 am

    So how does this: 

    “Chemicals in the drug itself, not the tobacco used in “joints”, were probably responsible since cigarette smoking had little effect on sperm morphology.


Rhyme with this:


”Drugs, tobacco and alcohol all have a range of short and long term health effects, including effects detrimental to the production of sperm. These effects include reduced concentrations of sperm in the semen and reduced concentrations of sperm which have a normal shape and are able to move or swim. Men who are trying unsuccessfully to conceive, and those who wish to protect the health of their sperm for the future, should therefore avoid a range of drugs, including alcohol and tobacco.


Now Google: “tobacco and sperm count”

  5. Jay Bosco   June 15, 2014 at 4:32 am

    Then where are all the damaged babies?

  6. Alun Buffry   June 15, 2014 at 3:46 am

    So how does this fit with the 60’s baby boom amongst the uk cannabis smokers and the populations of asia, africa and south america where cannabis is widely used?

  7. Hugh Stoner   June 14, 2014 at 8:42 pm

    You kidding me? 22 subjects? Really? Really? You left out the part of the study men who ejaculated in summer months showed the same results. In effect everybody. You kill me with such humorous studies that relies on honest answers about their auto erotic activities.
    This reminds me of the studies that said male users grew female breasts and It caused insanity in minorities causing uncontrollable lust and fornication along with the jazz music.
    Everyone I know smokes weed and have lots of young ones.

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