Celebrity doctor Daniel Amen says smoking weed can influence testosterone levels — and may affect men more than many realize.
A widely recognized brain specialist has outlined how cannabis use can impact the body, particularly when it comes to hormones that play a crucial role in male health. His explanation of how marijuana connects to various internal changes has fueled broader discussion about the drug’s growing popularity.
Surveys from 2023 found that roughly 17 percent of Americans reported smoking marijuana, and the drug is now legal in 24 states, with Ohio and Minnesota among the most recent to approve recreational use. While laws generally restrict cannabis to those 21 and older, many argue that teens still manage to access it with relative ease.
This ongoing concern has pushed experts to call for clearer information about how regular marijuana use might affect young, developing brains. Parents and health professionals continue to question whether long-term exposure could have consequences, even if the short-term effects seem less severe than those of other substances.
One major study tried to answer this by tracking 5,162 Danish men born between 1949 and 1961 across 44 years. Researchers examined how aging impacts cognitive health and whether early marijuana use contributed to long-term decline. More than half of the participants reported using cannabis before age 18, offering researchers a large comparison group.
The results showed that ‘the estimated difference in cognitive decline between cannabis users and nonusers was modest and may not hold clinical significance’. In simpler terms, using weed as a teenager did not appear to cause significant cognitive damage over the long term.
However, even though the study suggested limited effects on cognition, researchers emphasized that cannabis can influence men in other important ways — including testosterone. Experts note this area requires more attention due to the hormone’s impact on overall health.
According to Dr. Daniel Amen, cannabis use lowers testosterone in men. He explained that this trend isn’t driven by just one factor but appears across various lifestyle habits.
“We have this younger generation who has lower testosterone,” the celebrity doctor said on The Tucker Carlson Show podcast. “They’ve been getting lower and lower, so we have to ask ourselves ‘Why’s that?’”
He added that obesity is another major contributor to declining testosterone, pointing out that many people underestimate the hormonal effects of excess weight.
Dr. Amen explained: “Excess weight increases something called inflammatory cytokines. The fat on your belly is not your friend. It decreases blood flow, it increases inflammation. It prematurely ages your brain.”
“It takes healthy testosterone and flips it into unhealthy cancer-promoting forms of estrogen, which is why being overweight increases your risk of over 30 different cancers.”
Although Dr. Amen said he believes he can “conclusively” link marijuana use to lower testosterone, he also acknowledged that the research remains mixed. Studies continue to present different findings, keeping the debate open.
For instance, a 2018 study uncovered an unexpected result: healthy men who smoked weed just one to three times per month actually recorded the highest testosterone levels. These levels surpassed those of daily users and those who rarely consumed cannabis, suggesting the connection isn’t straightforward.
Another study, published in 2020, found that tetrahydrocannabinol (THC) — cannabis’s main psychoactive compound — was linked to small increases in testosterone, according to Men’s Health. However, researchers clarified that ‘this increase in [testosterone] appears to decline as THC use increases’, indicating that heavier consumption may reverse the slight boost seen with occasional use.
These conflicting findings highlight the complexity of the topic. Experts say that frequency, dosage, and individual biology all likely play a role — which explains why research often appears to point in multiple directions.
Taken together, the overall picture shows that the relationship between cannabis and testosterone levels is anything but simple. Some evidence points to decreases, some shows increases, and much of it emphasizes the need for more comprehensive research.
If you or someone you know needs confidential support for substance use, American Addiction Centers can be reached anytime at (313) 209-9137. Their website also offers private assistance.
