Now that's something to wrap your lips around. Vaping regularly can cause dry mouth, which can give you bad breath and damage the mouth, throat, teeth and gums. Some of PG VG Kaufen Vape Juice 101: Understanding PG VG Ratios And Nicotine Australia Vape Juice Vg Pg Ratio 25 Is the e cigarette hot and burning your lips? Terpy Does vaping cause mouth ulcers?; The Surprising Connection You Need to Mister Vape Do you know what you're vaping? Propylene glycol (PG) and vegetable glycerin (VG) are the main liquids in vapes. When heated, these chemicals turn toxic and aren't safe to breathe.