While this might sound a touch dramatic that a product as seemingly ubiquitous as apple cider vinegar could be so rough on your body, it's important to remember that at its core, ACV is vinegar. It's a highly acidic substance, so if you drink it on the regular, it can irritate your throat and wear away your tooth enamel , leading to mouth pain and discomfort. People who also take medications like diuretics or insulin , also have to be super careful with apple cider vinegar because it can interfere and lead to low potassium levels, according to the Mayo Clinic.