Adults who switched to nicotine-containing e-cigarettes were significantly more likely to quit smoking than those using nicotine-free versions, according to new research.

The study published in JAMA Network Open followed 104 people who smoked daily and wanted to quit. Participants were split into two groups and were either given e-cigarettes (also commonly referred to as vapes) with, or without nicotine.

Sixty-nine people completed the study, approximately equal numbers in the nicotine-free and nicotine-supplemented group. Participants assigned e-cigarettes with nicotine in them were three times more likely to quit smoking within six weeks than those given e-cigarettes without nicotine in them. Other than the nicotine content, the e-cigarettes were identical and study participants did not know which one they were given.

“For people who smoke and haven’t been able to quit using approved medications, this research suggests that switching to a nicotine e-cigarette is associated with real reductions in harmful toxicant exposures and does support smoking cessation,” said Jessica Yingst, associate professor of public health sciences at Penn State College of Medicine and lead author of the work. ”That’s a meaningful finding for public health."

The research looked specifically at pod-based salt-nicotine e-cigarettes. a popular type of product. The study also collected urine and blood samples from the participants to analyze biomarkers linked to exposure to toxic and cancer-causing chemicals found in tobacco smoke, finding significantly lower levels in the group which used the nicotine vape, indicating that these participants were smoking less.

The researchers emphasized that their work only looked at people who quit in the short-term. Research shows that around three quarters of people who manage to quit for 1-3 months eventually start smoking again. The researchers also stressed that their findings should not be misinterpreted as meaning e-cigarettes are in any way beneficial for non-smokers.

Many major health organizations including the American Lung Association and Centers for Disease Control caution that e-cigarettes still expose users to nicotine and other chemicals which can be harmful. There are also concerns that e-cigarette use by children and youth can lead to nicotine addictions and smoking tobacco products.

Nicotine is the addictive substance in tobacco and this is also present in other products designed to help people quit smoking, such as patches. The researchers noted that smoking addiction is not solely driven by nicotine dependence. Behavioral habits, including hand-to-mouth motion, inhalation and smoking rituals may also contribute to why quitting is difficult for many smokers. Because e-cigarettes replicate some of these behaviors, researchers suggest they may help some adults transition away from smoking.

“The way nicotine is delivered matters,” Yingst said. “The nicotine e-cigarette provides a similar level of nicotine as a cigarette, satisfying cravings and making the switch easier, but their overall toxic chemical exposure dropped substantially."