There is currently a hot debate among researchers on the existence of a link between marijuana and testosterone levels. Numerous studies result in controversial findings, though most of them conclude that marijuana does not cause any irreversible damage to male fertility. Here is what science can say about the effect of weed on your testosterone level.
The first study that investigated this issue was carried out by Jack H. Mendelson et al. in 1974. During the analysis, researchers monitored the testosterone levels of 27 men aged between 21 and 26 years. All participants consumed marijuana within a 21-day period. The findings revealed no statistical link between chronic marijuana use and reduced testosterone levels in plasma.
Another study published by the New York Times in 1981 discovered that marijuana impacted testosterone in two distinct phases. During the first stage, cannabis compounds raised the levels of sexual hormones, including testosterone, while the second stage brought a sudden drop of testosterone below the normal level.
Marijuana-related studies conducted by Robert C. Kolodny et al. in 1974 and by Harclerode J. in 1984 suggested that THC and other cannabinoids affected the production of the luteinizing and follicle-stimulating hormones. These hormones are essential for testosterone development. For instance, Kolodny discovered that frequent pot consumption over the period of six months reduced the testosterone level in males from 742 to 416ng/dL.
However, the results of a 1991 study showed no significant effect of marijuana on reproductive hormones. The study involved 93 males and 56 females who were divided into four groups according to the frequency of their marijuana use. The findings revealed no link between marijuana use and the level of testosterone, follicle-stimulating hormone, cortisol, prolactin, and luteinizing hormone.
Though not all researchers support the negative correlation between marijuana and testosterone levels, some of them are concerned about sperm quality in males who consume the substance.
Testosterone, along with other reproductive hormones, is crucial for sperm production, so Danish scientists investigated how marijuana affected the sperm quality of healthy young men.
In their 2015 study, they showed that consuming pot more than once per week reduced semen concentration by 28 percent. This decrease reached 55 percent in those participants who combined marijuana with alcohol. At the same time, pot consumers had higher levels of testosterone comparing to cigarette smokers.
Another study conducted in 2014 revealed that regular marijuana use led to the changes in male sperm. Young men aged under 30 had increased chances of producing abnormally shaped sperm after marijuana use, which might cause problems with sperm cells reproduction.
Additional studies have also discovered that THC can negatively impact such markers of fertility as sperm motility, capacity, quality, and count, which are quite important if you want to have a baby in the future.
Fortunately, researchers have also revealed that sperm is regenerated every 74 days, so a short abstinence from marijuana will return your fertility to its normal level.
There is also one more possible side effect of testosterone reduction caused by marijuana. Scientists at the National Institute of Health and the Mayo Clinic discovered a link between chronic herb use and gynecomastia in males. This disorder in the human endocrine system leads to the growth of men breast tissue known as “moobs.” Doctors linked this disorder to marijuana's impact on testosterone, but some studies showed that this reason of gynecomastia was quite contradictory.
Thus, further studies are necessary to provide more profound knowledge on this issue. As for now, it can be concluded that even if marijuana causes the reduction of testosterone levels in males, these side effects are short-term and reversible.