As more and more people try out vaping, researchers race to weigh health risks and benefits
The back wall is lined with hundreds of 10–15-mL eyedropper bottles, each with a colorful, eye-catching label announcing an enticing flavor. Melon head, razzletaz, serious kiwi, Swedish fish, gummy bear, taste the rainbow—the list goes on. The vials contain e-juice, a liquid concoction of varying amounts of nicotine, propylene glycol, glycerin, and food-grade flavorings. The juice is heated inside battery-operated, refillable devices that come in myriad sizes, colors, shapes, and styles. Nicotine in the e-juice, as well as any flavors, is aerosolized and inhaled by the user.