Latest Cochrane Review finds high certainty evidence that nicotine e cigarettes are more effective than traditional nicotine replacement therapy (NRT) in helping people quit smoking Cochrane E cigarette flavors are toxic to white blood cells, warn scientists E Cigarette Health Warning Sign FOR BOARDS OF HEALTH & TOBACCO RETAILERS ONLY English: Massachusetts Health Promotion Clearinghouse E Cigarettes Fact Sheet Center for Public Health and Tobacco Policy E Cigarettes and Pregnancy Maternal Infant Health CDC