yes it is as long as you are getting the safe ingredients from a reputable company. I shop at Dragonfly eCigs for example because they tell you the ingredients. It's a mix between flavoring and propylene glycol vegetable glycerin. Propylene glycol is safe because it is used in many household items including inhalers fog machines. Vegetable glycerin is used for cooking along with other household items. They mixed the vegetable glycerin and propylene glycol along with different flavors to make the juice which is heated and electronic cigarette to make water vapor not smoke or toxins. This small amount of nicotine that is at it has enough stimulation for your brain similar to caffeine and is therefore not harmful.