A new study on the effects of marijuana on sexual health has suggested that men could be courting sexual dysfunction from smoking it.
Study researcher Rany Shamloul, a physician with appointments at the University of Ottawa and Queen's University in Canada as well as the University of Cairo, conducted the study.
According to LiveScience, Shamloul said that even though research on the topic is contradictory, a recent study, including the finding that the penis contains receptors for marijuana's active ingredient, should make young men think of the long-term effects before rolling a joint.
Scientists first began to study marijuana and sex in the 1970s, and some researchers found that cannabis seemed to have the effect of a love drug.
In one 1982 study published in the Journal of Psychoactive Drugs, 75 percent of male pot smokers said the drug enhanced their sex lives.
Meanwhile, another study published in the same journal the same year found that erectile dysfunction was twice as common in marijuana.
Other research suggests a dose effect, in which small amounts of marijuana have little impact on sexual dysfunction, but more marijuana makes for fewer erections.
But problems are rife with this research, Shamloul said, because none of the studies used validated measurement techniques when surveying men about their sexual function.
What most concerns Shamloul is a study published in 2010 in the journal European Urology.
In that study, researchers found receptors for tetrahydrocannabinol (THC), the active ingredient in marijuana, in penis tissue from five male patients and six rhesus monkeys.
These receptors were mainly in the smooth muscle of the penis, Shamloul said. Additional lab studies suggest that THC has an inhibitory effect on the muscle.
"This is a more serious effect on the erectile function because the smooth muscle makes up 70 percent to 80 percent of the penis itself," Shamloul said.
Shamloul reported his findings online in the Journal of Sexual Medicine.