Exactly what is in vape juice? Vaping Ingredients Explained Gasping for Action A Watchdog Report Lab tests reveal popular e cigarette liquids contain harmful chemicals What Is in Vape Juice? [Key Ingredients Explained] Grey Haze UK E Liquid is made up of four basicingredients; water, nicotine, flavorings, and a propylene glycol or vegetable glycerin base (or sometimes a mixture of PG and VG). Nicotine Cigarets ingredients Acetaldehyde used to E liquid composition Vaping Post 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.