Image by Torben Hansen

Smoking pot may cause breast growth among men. This is according to Dr. Anthony Youn, a Detroit-based plastic surgeon.


Dr. Youn said that marijuana use could be the cause of breast growth among men. This is because of the effects of the drug on the hormone level.

“Gynecomastia is caused by a hormone imbalance between testosterone and estrogen,” Youn wrote. “When the ratio between testosterone and estrogen tips in favor of estrogen, the body responds by creating excessive breast tissue. Hence, man boobs,” he added.

Testosterone Levels

According to Dr. Youn, animal studies have shown that contact to tetrahydrocannabinol (THC), the active component in cannabis, can result in a decrease in testosterone levels. Some evidence show that male users of marijuana have lower testosterone levels than non-users.  Heavy doses of drugs, on the other hand, may delay the onset of puberty in young men.

There haven’t been any definitive evidence to confirm the connection between pot-smoking and man boobs, but Youn, and sites like and MedlinePlus, still suspect a link between the two. On MedlinePlus, “marijuana use” is among the causes of Gynecomastia.