People who smoke cannabis are getting 20 per cent more nookie than the rest of us, scientists claim.
Stoners are known for their mellow laid back attitudes and it had been suggested their constant cannabis smoking made them a flop in bed.
But rather than being disinterested in sex and unable to perform between the sheets, a new study found frequent marijuana smoking did not inhibit their sexual desire or sexual prowess.
In fact they had more sex having at least one more session of love making in four weeks than those who do not partake in a spliff. Overall they had a fifth more.
And the more they smoked, the more sex they had, the study of more than 50,000 Americans ages 25 to 45 by the Stanford University School of Medicine found.
Senior author assistant professor of urology Dr Michael Eisenberg said: "Frequent marijuana use doesn't seem to impair sexual motivation or performance.
"If anything, it's associated with increased coital frequency."
And the findings applied across of sectors of society and he added: "The overall trend we saw applied to people of both sexes and all races, ages, education levels, income groups and religions, every health status, whether they were married or single and whether or not they had kids.
"Marijuana use is very common, but its large-scale use and association with sexual frequency hasn't been studied much in a scientific way."
He said the trend of having increased sex remained even after accounting for the use of other drugs, such as cocaine or alcohol.
This suggested marijuana's positive correlation with sexual activity doesn't merely reflect some general tendency of less-inhibited types, who may be more inclined to use drugs, to also be more likely to have sex.
But Prof Eisenberg cautioned the study shouldn't be misinterpreted as having proven a causal link and said: "It doesn't say if you smoke more marijuana, you'll have more sex."
The study was the first to examine the relationship between marijuana use and frequency of sexual intercourse at the population level in the United States.
It is estimated 20 million Americans smoke marijuana and as more states legalise it numbers are increasing.
But its effect on sex lives remain disputed.
On the one hand it is said to cause erectile dysfunction in heavy smokers and rigorous studies have found reduced sperm counts in men who smoke it.
Yet on the other hand, experiments conducted in animal models and humans indicate marijuana stimulates activity in brain regions involved in sexual arousal and activity.
So Prof Eisenberg and lead author Dr Andrew Sun, a resident in urology, looked at the National Survey of Family Growth which contains data on family structures, sexual practices and childbearing.
Specifically the annual survey since 2002 asked men and women how many times participants had intercourse with a member of the opposite sex in the past four weeks, and how frequently they've smoked marijuana over the past 12 months.
The answers were obtained from 28,176 women with an average age of 29.9 and 22,943 men with an average age of 29.5.
It found a quarter of men - 24.5 per cent - and a sixth of women - 14.5 per cent - said they used cannabis and there was a positive association between the frequency of marijuana use and the frequency of sexual intercourse.
Those women who said they did not use the drug in the past year had sex on average 6 times during the previous four weeks, whereas that number was 7.1 for daily pot users.
Among men, the corresponding figure was 5.6 for nonusers and 6.9 for daily users.
In other words, pot users are having about 20 per cent more sex than pot abstainers, Prof Eisenberg noted.
The study was published in the Journal of Sexual Medicine.