What's In Your Vape Juice? E Liquid Ingredients Explained EDGE Vaping The Chemistry of Vaping ChemistryViews Buy Vape Starter Kits & E Cigarette Starter Kits Juicemate What's in an e liquid or vape juice? The main ingredients are propylene glycol (PG) and vegetable glycerine (VG). These are solvents that are basically used to dissolve and carry the other ingredients. Teen Health Info : Vaping everything you need to know