By the 11th century, medieval healers were still looking to Hippocrates, Galen and other ancient doctors whose teachings had been translated by monks into Latin and compiled into the great medical tome Regimen Sanitatis Salernitanum. This compendium of all medical knowledge prescribed wine and other alcoholic beverages for everything from indigestion to insanity. And it tells you exactly what to do should you exceed the recommended dose. “If you develop a hangover from drinking at night, drink again in the morning. It will be your best medicine.”

It was a concept popular to all forms of medical treatment: fight fire with fire, yet do no harm. A tricky combination, but one that people have been attempting forever.And of course, booze was the least questionable ingredient in many curative elixirs. The Dispensatorium Pharmacorum, a medical dictionary from the mid-16th century, contains recipes that combine wine with ingredients such as the ashes of scorpions, dog excrement and wolf’s liver. And an article from The London Distiller in 1667 explains how to make an apparently well-known tonic from a crushed human skull: “Take the Cranium-Humanum as you please, break it into small pieces . . . then put string fire to it by degrees, continuing until you see no more fumes come forth; and you shall have a yellowish spirit, a red Oyl, and a volatile salt.” The resulting liquor is supposed to help with “the falling-sickness, Gout, Dropsie, infirm Stomach; and indeed strengthens all weak parts, and openeth all obstructions, and is a kind of Panacea.”

If, however, your hangovers tend to be accompanied by tinges of remorse, you might want to avoid getting drunk on crushed human skull. But then again, there’s always this for the morning after, from Andy Toper’s list of ancient hangover cures: “In Old Europe it was widespread to cultivate moss inside a skull, dry it, powder it, then snort it”—a bit of the skull that bit you.

It is also possible that, at certain times and places in history, whole towns, cities and civilizations never got a chance to be hungover—they just kept a slight buzz going all day, then into the next, apparently without a lick of guilt.

Today, it is this aspect—the degree to which your hangover makes you feel guilty—that may decide what kind of hair of the dog you choose: a warm, stale beer, a spicy Bloody Caesar or one of countless cocktails invented specifically for this purpose. Such concoctions tend to come in two overarching categories: sweet, soft soothers meant to ease you back to baseline with something milky, fruity, relaxing and restorative (these have names like Morning Glory, Milk of Human Kindness and Mother’s Little Helper), or short, sharp shocks intended to twist your system into sobriety with bitterness, blinding heat and/or gag reflex (Khan’s Curse, Suffering Bastard, Guy Fawkes’s Explosion . . .).

Historically, this second variety could contain anything from anchovies to ammonia, garlic to gunpowder. As Clement Freud (sounding more than a little like his overly analytical uncle) puts it, such tonics also “sublimate any guilt feelings” by subjecting an already remorseful bastard to a more precise moment of suffering: “Liquid cures of this type,” he opines, “owe much of their effectiveness to the popular belief that anything that tastes really disgusting must actually do you good.”

But guilt feelings aside, does a hair of the dog make practical sense? Sure it does, and always has. Even the National Institutes of Health in the US admit that “the observation that alcohol readministration alleviates the unpleasantness of both AW (alcohol withdrawal) and hangovers suggest that the two experiences share a common process.”

At certain times and places in history, whole towns, cities and civilizations never got a chance to be hungover—they just kept a slight buzz going all day, then into the next, apparently without a lick of guilt.But in regards to “readministration,” those in such institutes also warn you should never, ever do it, lest you turn into a certified drunk. In 2009, Dutch researcher Dr. Joris Verster published a paper addressing precisely this. “The ‘Hair of the Dog’: A Useful Hangover Remedy or a Predictor of Future Problem Drinking?” was based on a survey of Dutch undergrads. It revealed, among other things, that those who used alcohol as a morning-after treatment consumed approximately three times as much alcohol, and that those who did so more often had “a significantly higher lifetime alcohol dependence diagnosis.” But of course, there’s an aspect of chicken-and-egginess to all of this. And also, Verster’s paper never did tackle the first part of the question: “A Useful Hangover Remedy?”

The hair of the dog may, in fact, work in ways we never imagined. In Proof, Adam Rogers’s excellent recent book about the science of alcohol, the author suggests that “ethanol might help with a hangover because it stops the body from breaking down methanol.” As Rogers explains it, ethanol is the magical essence of alcohol, while methanol is a nasty molecule that, at low levels, sneaks into most alcoholic drinks and, at high levels, might just kill you. Broken down, it becomes the poison known as formaldehyde. While recognizing that some studies dismiss its effects, Rogers concludes that “one piece of evidence is suggestive: the relative efficacy of the ‘hair of the dog’—drinking more booze.”

It is likely—in fact, probable—that one Frank M. Paulsen of Wayne State University has cataloged more hairs of the dog than anyone else in history. In 1960, Paulsen went in search of the elusive hangover cure—or, at least, the myths surrounding it. His research was exhaustive, yet inspiringly rough-and-tumble. He traveled to dive bars, roadhouses and nightclubs in Detroit, Cleveland, Montpelier, Buffalo, Utica, Omaha, Los Angeles, Quebec, Montreal and Toronto. And he asked for people’s advice.

Guilt feelings aside, does a hair of the dog make practical sense? Sure it does, and always has.

Many of his subjects remained anonymous, since, in his words: “I was unable (or thought it unwise as the case might be) to ask for names and biographical information from over half my informants. The subject matter of the cures and the places where they were collected should justify this high degree of anonymity.”

The resulting study, “A Hair of the Dog and Some Other Hangover Cures from Popular Tradition,” was published the following year in the Journal of American Folklore, and nowhere else since. It is 18 pages of poetical brilliance: as if Charles Bukowski and Tom Waits sat down to write a story or a song together, then got very, very sidetracked.

Paulsen has a way with people. You can see them opening up to him with a laugh, and you can smell the gin on their breath. And he seems to have hit on a sort of apex in the history of morning-after drinks. Here are a mere five of the 261 hairs he found on his big dog trip—along with descriptions of his interviewees, which, a half century later, thanks to Paulsen’s poetic precision, are just as telling as what they had to say:

Cut a big piece of watermelon, if you can get hold of one, and punch holes in the meat with a fork. Pour half a pint of gin over that and eat it down. Be careful of the seeds; they’ll kill ya.

—Mr. Meschner, Hawkins Bar, Detroit. Retired; white, male, about 70; born and raised in Detroit, where he worked for the Ford Motor Company for some 50 years; now spends most of his time wandering from bar to bar in the northwestern section of Detroit; quite active for a man his age.

Eat a white Bermuda onion like an apple. Wait half an hour, then take a good shot.

—George Gust, Club 58, Cleveland. Restaurant and bar owner, white, male, about 28; of Greek extraction.

A shot and a beer—a stale beer if you’ve got any. Break a couple eggs and put them in the beer. Don’t eat the eggs. Let [the hangover] fight itself out. But if you get hungry after a couple of doses, eat the eggs.

—Anonymous, Webb Wood Inn. Occupation unknown; white, male, about 65; apparently quite a heavy drinker.

Take cold, jellied consommé and mix in some Worcestershire, celery salt, garlic powder, and about four ounces of vodka. Your secretary will hate you, but you’ll be able to get through till lunch.

—Anonymous, Club 58, Detroit. General Motors executive; white, male, about 45.

Mix cinnamon in wine and sip on it. Any kind of sweet wine will do.

—George Fonte, Club 58, Buffalo. Bartender; white, male, about 45; born and reared in Wisconsin; has been tending bar, mostly at exclusive private clubs for 20 years; he was my most cooperative and informative informant. (Fonte also suggested: milk; lemon sherbet; mashed strawberries and sugar dressed with egg whites, gin and chartreuse; a whisky sour; salty dogs; an orange blossom; a shot of vodka mixed with equal parts tomato juice and clam juice; sherry mixed with an egg yolk and served at room temperature; a shot of Pernod mixed with an egg white and four dashes of bitters; and warm seltzer water mixed with bitters.)