text: where does the expression "hair of the dog" come from and why is it connected to drinking alchohol?   the phrase "hair of the dog" is used to refer to a drug consumed with the intent of lessening or postponing the effects of withdrawal from that drug. for example, it is frequently used to refer to alcoholic beverages consumed with the intent of lessening the effects of a hangover. it is a shortened form of the phrase "the hair of the dog that bit you". the phrase is reported to come from the folklore belief that burning the hair or consuming a concoction involving the hair of a dog that has bitten a subject would prevent the subject from becoming afflicted with the diseases (namely rabies) that the dog may carry.