Vape Juice Ingredients: All You Need to Know The Chemistry of Vaping ChemistryViews 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. Chemical characterisation of the vapour emitted by an e cigarette using a ceramic wick based technology Scientific Reports Vape Flavors and Vape Juice: What You Need to Know Johns Hopkins Medicine