The Science of Hangovers

It is a cruel irony that the fun of a night of drinking tends to be directly correlated to the level of misery we experience the morning after. And as we get older, it doesn’t get any easier. “At some point,” Dan Brooks wrote in The New York Times Magazine, “we discover that innocent behaviors, like drinking 10 beers and yelling about the Hold Steady until the lights come on, now result in terrible consequences.”

Science has figured out a lot of things — the birth of the universe; cures for diseases; and, magic devices that allow us to communicate with friends, read about hangovers, and argue with strangers on Twitter from just about anywhere. Surely there must be some way to enjoy the revelry of a boozy evening without all the head-throbbing hell of a hangover the next day.

But, until recently, there had been distressingly little serious scientific effort put towards the study of hangovers.The science of why we get hangovers has been mostly an educated guess. Happily, things are starting to change. Over the past few years, researchers have begun to put a dent in the fog surrounding our post-drinking foggy-headedness.

We should all know by now that heavy boozing can have lots of terrible consequences beyond just hangovers. It can cause health problems and prompt bad decisions with life-changing consequences too.

National Institutes on Alcohol Abuse and Alcoholism

The upside of drinking is that alcohol triggers a release of dopamine and urges to dance on tables and hug your friends while slurring something about “I love you man!” The effect is particularly pronounced in the nucleus accumbens, one of the brain’s pleasure centers and the amygdala, a part of the brain that stores memories of the bad things that happened last time you got drunk and thought it was a neat idea to jump off a hotel balcony into a swimming pool. But, drinking also has effects on the brain and the rest of the body that makes the next day a living hell.

Dehydration is Only Part of It

Dehydration has long been among the more popular explanations for hangovers. But, it turns out that may be wrong — or at least not completely right. Dehydration probably does play some role. Alcohol suppresses vasopressin, an anti-diuretic hormone produced by the pituitary gland that promotes reabsorption of water by the kidneys. A dearth of vasopressin causes the kidneys to allow more water to pass into the bladder rather than being returned to the body, an effect easily observed in the long late-night bathroom lines at bars. In short, and this should come as a surprise to no one, you pee more when you’re drunk. For every refreshing Hendricks’ gin and tonic you drink, you’ll lose anywhere from two to four times as much water.

Dehydration tends to cause headaches, dizziness and other unpleasantries. Still, dehydration alone does not account for the singular agony of a raging hangover. Drinking water or sports drinks will make a hangover a bit less brutal, but it won’t cure it. There must be more too it.

Hangovers and the Brain

You rarely get a hangover while you’re drinking. The hangover starts only after your blood alcohol concentration begins to fall. In fact, hangover severity reaches its peak when blood alcohol levels fall to zero. This provides an important clue.

A typical hangover may just be a milder version of the alcohol withdrawal syndrome suffered by alcoholics who give up the bottle. Which is why the “readministration of alcohol” — science-speak for a morning after Bloody Mary — tends to temporarily make things better. The exact mechanisms for how this happens are just beginning to be understood.

Ethanol in booze binds to nerve receptors normally occupied by gamma-aminobutyric acid (GABA), an important neurochemical messenger that calms brain activity. Awash in GABA-like ethanol molecules after that last round of beer pong, to keep everything in balance, the brain cuts back on GABA and kicks production of an excitatory neurotransmitter called glutamate into high gear.

Meanwhile, down in the liver, your body is furiously filtering out the alcohol you’ve filled it with over the course of the evening. As the alcohol departs, your brain is left with a deficit of GABA and a surplus of high-octane glutamate. The imbalance sends the nervous system into an overexcited state, which is why you wake up suddenly in the night after drinking.

Richard Olsen, a neuro­scientist at UCLA has been studying these neurophysiological effects with an eye towards developing a hangover cure. Olsen thinks a compound that blocks alcohol from acting on certain GABA receptors could mitigate its unpleasant after-effects — and he’s found a promising lead.

Jing Liang, one of Olsen’s graduate students, began testing Chinese herbs traditionally associated with moderating the effects of alcohol. Liang discovered that one herb, called Hovenia, contains a molecule called dihydromyricetin that acts on the right GABA receptor. Controlled experiments with dihydromyricetin in rats and not-so-controlled experiments conducted by Liang, Olsen and their colleagues at local bars following scientific conferences have shown promise.

“Jing [Liang] gave a talk at a meeting about our results, and we invited our friends to the bar afterward to try it out,” Olsen told Wired. “Now, this is not publishable, and you can’t use it for evidence for the FDA, but it’s good for us to know what kind of dose we should be using in our clinical trial—and that it doesn’t hurt anybody and does something to us that we want.”

The scientists who took dihydromyricetin before drinking reported feeling less drunk, and less hangover the next day, according to Wired.

Several anti-hangover supplements are now on the market boasting dihydromyricetin as an active ingredient.

Another group of researchers led by Dutch scientist Joris Verster, have styled themselves as the Alcohol Hangover Research Group, or AHRG for short. AHRG has been developing some important new science on the topic. They even made a logo — a beer and an empty wine glass lying on its side.

Verster and his AHRG colleagues favor a theory that actually an inflammatory response is a likely culprit. Studies have found elevated levels of cytokines, which are signaling molecules released in response to trauma and inflammation, after drinking. It turns out, that injecting cytokines in otherwise healthy people creates symptoms that closely resemble a hangover. As Adam Rogers wrote for Wired:

A team in Korea noticed that hangovers are accompanied by elevated levels of molecules called cytokines, which are used as communication signals by the immune system. If you inject those into a healthy subject, that person will start to have all kinds of familiar-sounding symptoms, including nausea, gastrointestinal distress, headache, chills, and fatigue. Potentially even more interesting, higher-than-normal cytokine levels also interfere with memory formation—which might account for ethanol-­related lapses in recall as well.

This explains why Nonsteroidal Antiinflammatory Drugs (NSAIDs) such as Ibuprofen work reasonably well at moderating the effects of hangovers. Perhaps more sophisticated anti-inflammatory drugs could be developed that work even better.

Another contributing factor might be acetaldehyde, which is produced as alcohol is metabolized in the body. Most people break it down before it becomes much of a problem. But, acetaldehyde is toxic and if you drink enough, you’ll probably be hugging the toilet as your body tries to expel it.

Trace chemicals and impurities called congeners may also contribute to hangovers too. Joris Vester studied these effects and created this useful chart:


Methanol, a byproduct of fermentation found in higher levels in whiskey and red wine, might be part of the reason these drinks cause worse hangovers than high-quality vodkas, which have almost no congeners at all. Sugary drinks could also trigger blood sugar effects that compound the consequences.


Let’s be clear, getting blitzed is not a great idea. But, if you must, science is here to help:

  • Drink High-Quality Vodkas — Higher-end vodkas with fewer congeners are less likely to produce hangovers. If you’re going to drink a lot, splurging on the top-shelf stuff may be worth it. Avoid bourbons, which contain the most congeners. Also, binge drinking red wine, which also contains a lot of congeners, isn’t the brightest move either.
  • Drink Lots of Water — Dehydration isn’t the only cause of a hangover, but every little bit helps. Drinks with lots of electrolytes like Pedialyte and Gatorade are good too.
  • Take NSAIDS — Taking a couple ibuprofen or aspirin before bed after drinking can work wonders. Just don’t take Tylenol. It inhibits liver function and can theoretically kill you if you take it while drinking.
  • Hair of the Dog May Work…Temporarily — It’s merely delaying the inevitable, but if you want to fend off your hangover for a bit longer, and you haven’t had too much, a few mimosas might help.
  • Dihydromyricetin Supplements — Although there are as yet no conclusive studies, they seem to work in rats and, at least anecdotally, seem to help with people too.

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