JUUL Pod Ingredients: What's in E Cigarettes? Nicotine isn't the only hazard to be found in e cigarettes Chicago Tribune E Cigarettes, Vapes, and other Electronic Nicotine Delivery Systems (ENDS) FDA E cigarettes are not a healthier alternative to cigarettes. They contain nicotine and many harmful ingredients that can cause cancer and heart disease. Since these products are relatively new, we don't know all Health Warnings on E Cigarettes May Improve Perception of Risks MedPage Today