Drugs Study: Cannabis use increases testosterone in young men
Contrary to previous assumptions, cannabis use does not lower testosterone levels in young men. Instead, a study by the University of Geneva has found an increase in the hormone. This has no effect on fertility.
28.05.2026, 12:27
SDA
The researchers analyzed blood samples from 94 Swiss recruits between the ages of 18 and 23, as the University of Geneva (Unige) announced on Thursday.
The results showed around 23 percent higher testosterone levels in the 47 cannabis users compared to the 47 non-users.
According to the authors of the study, the cause of this increase can be found specifically in the testicles. The production of male sex hormones, the androgens, in the adrenal glands was not affected. Cannabis therefore appears to have a direct effect on the Leydig cells in the testicles, which produce testosterone.
No direct link to fertility
However, the researchers warned against interpreting the increase in hormone levels as an indicator of better sperm quality. The relationship between testosterone and fertility is very complex.
The observed increase could be a compensatory reaction of the body to a reduced sensitivity of certain hormone receptors. It is also possible that men with naturally higher testosterone levels are more prone to risky behavior and thus to cannabis use.
Although cannabis appears to influence certain biological mechanisms of reproduction, the exact clinical consequences for the fertility of young men remain unclear, the press release continues. Further research is needed to assess possible long-term effects.
The study was conducted in collaboration with the Swiss Center for Applied Human Toxicology in Basel. The results were published in the journal "Communications Medicine".
The results confirm earlier large-scale studies from Denmark and the USA, which also found a link between cannabis use and higher testosterone levels. Older, smaller studies had suggested contradictory or opposite effects in some cases.
