does pot lower testosterone

Frequently asked questions

Male fertility:
Do cannabis or THC have a negative influence on sex hormones and sperms?

    Wayne Hall, Nadia Solowij & Jim Lemon
    High doses of THC probably disturb the male and female reproductive systems in animals. They reduce secretion of testosterone, and hence reducing sperm production, motility, and viability in males. It is uncertain whether these effects also occur in humans. Studies in humans have produced both positive and negative evidence of an effect of cannabinoids on testosterone, for reasons that are not well understood. Hollister has argued that the reductions in testosterone and sperm production observed in the positive studies are probably of “little consequence in adults”, although he conceded that they could be of “major importance in the prepubertal male who may use cannabis.” The possible effects of cannabis use on testosterone and spermatogenesis may be most relevant to males whose fertility is already impaired for other reasons, e.g. a low sperm count.
    (Please note: This text has been taken from a scientific article. Some sentences have been changed to improve understandability.)
    Hall W, Solowij N, Lemon J. The Health and Psychological Consequences of Cannabis Use. National Drug Strategy Monograph Series No. 25. Canberra: Australian Government Publishing Service, 1994.

Laura Murphy
In human males, cannabis smoking has been shown to decrease blood levels of the three hormones LH, FSH, and testosterone. Moreover, an increased incidence of low sperm count has been reported in men who were heavy marijuana smokers. Other studies did not find measurable differences in men who were light or heavy marijuana users. Acute THC treatment produces a consistent and significant dose- and time-related decrease in LH and testosterone levels in male rodents. In the male rhesus monkey, an acute dose of THC produced a 65% reduction in blood testosterone levels by 60 min of treatment that lasted for approximately 24 hr.
(Please note: This text has been taken from a scientific text. Some sentences have been changed to improve understandability.)
Murphy L. Hormonal system and reproduction. In: Grotenhermen F, Russo E, eds. Grotenhermen, F., Russo, E. (eds.): Cannabis and cannabinoids. Pharmacology, toxicology, and therapeutic potential. Haworth Press, Binghamton/New York 2001, in press.

Lynn Zimmer & John Morgan
By giving large doses of THC to animals, researchers have produced appreciable effects on sex hormone levels. However, the effects vary from one study to another, depending on the dose and timing of administration. When effects occur, they are temporary. (. ) In neither male nor female animals have researchers produced permanent harm to reproductive function from either acute or chronic marijuana administration. (. ) There is no convincing evidence of infertility related to marijuana consumption in humans. There are no epidemiological studies showing that men who use marijuana have higher rates of infertility than men who do not. Nor is there evidence of diminished reproductive capacity among men in countries where marijuana use is common. It is possible that marijuana could cause infertility in men who already have low sperm counts, However, it is likely that regular marijuana users develop tolerance to marijuana’s hormonal effects. (. ) Marijuana has neither a masculinizing effect in females nor a feminizing effects in males.
Zimmer L, Morgan JP. Marijuana Myths Marijuana Facts. A review of the scientific evidence. New York/San Francisco: The Lindesmith Center, 1997.

House of Lords
Animal experiments have shown that cannabinoids cause alterations in both male and female sexual hormones; but there is no evidence that cannabis adversely affects human fertility, or that it causes chromosomal or genetic damage.
House of Lords Select Committee on Science and Technology. Cannabis. The scientific and medical evidence. London: The Stationery Office, 1998.

Frequently asked questions Male fertility: Do cannabis or THC have a negative influence on sex hormones and sperms? Wayne Hall, Nadia Solowij & Jim Lemon High doses of THC

Could Smoking a Little Pot Raise Sperm Levels?

By Dennis Thompson

HealthDay Reporter

WEDNESDAY, Feb. 6, 2019 (HealthDay News) — Forget the mellow slacker image — pot smoking might actually make men more potent.

Men who’ve smoked marijuana appear to have significantly higher sperm concentrations than those who’ve never given it a try, a new study reports.

There’s also a potential link between pot use and testosterone, said senior researcher Dr. Jorge Chavarro. He’s an associate professor of nutrition and epidemiology at the Harvard T.H. Chan School of Public Health in Boston.

“With increasing use of marijuana, there was a positive association with serum testosterone levels,” Chavarro said. “More marijuana, higher testosterone levels.”

Couples shouldn’t start smoking pot to improve their chances of conception, however.

This was an observational study, and it’s entirely possible that the link between pot and male fertility might run in the opposite direction, Chavarro said.

“We know that men with higher testosterone levels tend to engage in risk-tasking behaviors. The higher your testosterone, the more likely you are to do risky stuff,” like frequent pot smoking, Chavarro said.

Chavarro and his team set out to study the possible effects of pot smoking on male reproduction by observing 662 men enrolled at the Massachusetts General Hospital Fertility Center in Boston between 2000 and 2017.

Semen samples were taken from all of the men, and 317 provided blood samples that were analyzed for reproductive hormones. The men also filled out a questionnaire about their marijuana use.

Fifty-five percent of the men said they’d smoked pot at some point, with 44 percent saying they were past smokers and 11 percent reporting they currently toke.

The researchers had hypothesized that marijuana use would be associated with lower semen quality, so they were surprised to learn that pot smokers had higher sperm concentrations.

Current and past marijuana users had average sperm concentrations of 62.7 million sperm per milliliter of ejaculate, while men who had never smoked marijuana had average concentrations of 45.4 million sperm per milliliter.

Only 5 percent of marijuana smokers had sperm concentrations below 15 million, the World Health Organization’s threshold for “normal” levels. By comparison, 12 percent of men who never tried marijuana had below-normal sperm levels, the findings showed.


These findings were “unexpected and surprising,” Chavarro said.

“We spent a couple of months doing analysis to figure out if we had done something wrong,” he added. “As far as we can tell, this is what the data is showing. Now the question is: What does it mean?”

Animal studies have shown that cannabinoid receptors play a part in the male reproductive system, Chavarro said. It could be that marijuana complements or boosts the role played by cannabinoids that are naturally produced within the body.

Or it could just be that guys with higher testosterone levels are more likely to smoke pot, as part of an overall pattern of risk-taking, he suggested.

Dr. Norbert Gleicher, medical director and chief scientist at the Center for Human Reproduction in New York City, said “it’s too preliminary” to say whether pot would help or harm a man’s fertility.

“What this study shows is pot smoking doesn’t make you automatically infertile, but there have been studies on pot smoking for many years and there are a good number of studies out there that indeed have reported adverse effects on semen in pot smokers,” Gleicher said.

“It requires further investigation, and I would argue those investigations have become more urgent now because pot has become more legalized,” he added.

And pot smokers might not necessarily have a better chance of conception just because their sperm concentrations are higher, said Dr. Jennifer Kawwass, medical director of the Emory Reproductive Center in Atlanta.

Although there are more sperm, their quality might be affected by marijuana use in ways that remain undetected.

“It is important to understand that the difference in sperm concentration between light smokers and never-smokers is not necessarily associated with a difference in fertility potential,” Kawwass said.

The new study was published Feb. 6 in the journal Human Reproduction.

Men who’ve smoked marijuana appear to have significantly higher sperm concentrations than those who’ve never given it a try, a new study reports.