Is the secret to cutting back on smoking found in pot? A study by a team of researchers at the Clinical Psychopharmacology Unit in London’s University College, published in the April issue of Addictive Behaviors, finds that inhaling the marijuana-derived substance cannabidiol significantly reduces the number of cigarettes a smoker lights up.

Cannabidiol derives from cannabis plants, but unlike tetrahydrocannabinol (THC), the active ingredient in pot, it does not have psychoactive properties. It does, however, seem to reduce the urge to smoke.

The researchers randomly assigned half of 24 smokers an inhaler dosed with cannabidiol and half with placebo inhalers, and instructed them to take a hit off the inhaler whenever they felt an urge to smoke. A week later, those using placebo inhalers showed no differences in the number of cigarettes they smoked, whereas those huffing on the cannabidiol cut their cigarette consumption by about 40 percent. This is potentially very good medicine: A 2005 study in the Journal of the American Medical Association reported that cutting down from a pack a day to half that reduces the risk of lung cancer by 27 percent.