Last Monday morning, I woke up with a pounding headache, dry mouth, and bloodshot eyes. When I sat up, covered in sweat, my immediate thought was, "What on Earth did I drink last night?" For better or for worse, I wasn't actually hungover — I was on day one of a vicious flu. But for some reason, the phrase "hair of the dog" was pinging though my brain like a relentless earworm for the remainder of the week.
The truth is, I haven't been seriously hungover in a few years. The older I get, the longer it takes me to recover, so I avoid one at all costs. I make sure I eat, try to balance my liquor with water, and settle my tab early.
But the more I've thought about "hair of the dog," the more I've wondered where the expression originated. As I sweated through my illness on the couch, covered in actual dog hair — my pit mix is white and black, so I'm always showing the evidence — I learned that the linguistics come from a Scottish theory in which you apply a few "hairs of the dog that bit you" to an open wound to ward off consequences. The concept actually dates back to the Latin medical ethos "like cures like," as documented by Greek physician Hippocrates in around 330 B.C., who may have picked it up from ancient writings from Ugarit, a port city located in what is now Syria. There, around the second millennium B.C., a god recovering from a drinking binge applied a blend of olive oil, plant pieces, and, yes, dog hair to his forehead.
Further digging shows that "hair of the dog" is a universal idiom. Hungarians, Irish, Mexicans, and Costa Ricans all refer to it. Germans, Swedes, and Danes prefer to call next-day drinks "counter-beers," "repairs," and "restorers," while Chinese drinkers describe the hangover remedy as "the drink that brings back your soul." Similarly, during the Great Depression, drinks like "Corpse Revivers" were in high fashion.
However you refer to it, hair of the dog has real potential to reduce the severity and longevity of a hangover. You stop drinking, usually because you fall asleep, and by the time you wake up, you're severely dehydrated, and, as reported in Medical Daily, "an inflammatory response from the immune system can inhibit memory, concentration, and appetite." Plus, booze has a direct effect on your blood sugar, which makes you feel shaky after an evening of drinking.
Doctors won't recommend it, but a shot of hard liquor can dull the worst parts of a hangover so that you can get moving again. Try this only if you have a fully stocked kitchen; as soon as you put down your shot glass, start scrambling some eggs and making toast to soak up the liquor in your system. If you make it out for brunch instead, ordering a bloody mary with your meal might help reset your system. The spices will sharpen most of your senses, while the vodka takes the edge off others. And the vitamin-packed juice just might (the theory is disputed by some scientists and approved by others) help you metabolize whatever alcohol is still sloshing around your liver.
Science journalist Adam Rogers, an editor at Wired magazine and author of the fabulously witty 2014 tome Proof: The Science of Booze, has both feet firmly planted in the "hair of the dog" camp. To put it more succinctly, Rogers promotes the hypothesis that "If a hangover is methanol toxicity, you're going to have another drink, and the ethanol displaces the methanol off the enzyme and you will feel better." The trick is to not just resort to drinking more, but to add a meal of complex carbohydrates, plenty of water, and, preferably, a nap to undo a bad hangover.