There have been contradicting findings on the research on sexual health and marijuana use. But a review of some of the major studies on the topic found that pot smoking may actually dampen men`s libido.
The research by a team from the University of Ottawa and Queen`s University in Canada found that erectile dysfunction was twice as common in marijuana users.
"It`s a strong message to our younger generations and younger men," study researcher Rany Shamloul told LiveScience.
Scientists first studied the co-relation between marijuana and sex in 1970s and found that cannabis ups sexual desire, and has an effect similar to love drug.
In a research, published in 1982 in the Journal of Psychoactive Drugs, 75 per cent of men said that pot smoking prior to sex enhanced their performance on bed.
Meanwhile, another study published in the same journal the same year reported that erectile dysfunction was twice as common in marijuana smokers.
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 we are really missing are clinical studies.
"We are stuck with only animal studies and molecular studies, and some clinical studies done in the 60s and 70s, most on a very small number of men. We need well-designed, placebo-control studies examining marijuana`s effect in both the short-term and long-term," he said.
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 per cent to 80 per cent of the penis itself," Shamloul said.
Marijuana use is widespread, especially among men at their sexual peak in life, Shamloul said.
The United Nations Office on Drugs and Crime reports that 162 million people worldwide use marijuana each year. More than 22 million use it daily.
The new findings were appeared in the Journal of Sexual Medicine.