Does hair of the dog actually work?

When you’ve overdone it on the festive drinks and wake up with the familiar dry mouth, pounding head and weak limbs, is the best way to feel human again to drink more?

Research shows that when it comes to hangovers, us Brits seem to suffer more than other nationalities, with nearly two in 10 of us struggling with hangovers after drinking.

This means there are going to be a lot of sore heads over the festive season – particularly on 1 January.

If you’re feeling the repercussions after celebrating, you might be tempted to try the hangover ‘cure’ best known as hair of the dog. But does it really work? We spoke to experts to see if there is any science behind the theory and find out what else might help rid you of that headache, tiredness and nausea.

The symptoms we’re so desperate to get rid of

Before we get into how to relieve our hangover, let’s look at why many of us are so keen too. Symptoms vary from person to person, but there are a core few that seem to be universal.

“The most commonly experienced hangover symptoms reported are tiredness, thirst and headache,” says Sam Royle, a researcher at University of Salford and part of the Alcohol Hangover Research Group.

Dizziness or faintness, loss of appetite, stomach ache, nausea and a racing heart are also common he says, pointing to research carried out in 2012 by Renske Penning and colleagues.

“As many as 47 different symptoms have been investigated in research on hangovers,” Royle says. And while some of these will be familiar to most of us, there are others that seem to impact only an unlucky few.

“Some of the less common symptoms that have been investigated include respiratory problems, heart palpitations and anxiety. In the 2012 research, 1.8% of participants reported some level of suicidal thoughts following their most recent night out, though it’s important to note that we don’t know whether there were other factors that might be important in such extreme symptoms, such as pre-existing issues.”

Dr Lauren Owen, head of the Nutrition Psychopharmacology and Brain Development Unit at University of Salford, mentions another lesser-known health complaint: “In East Asian populations, there is a relatively common symptom of ‘flushing’ that is absent in other populations of the world. This genetic condition, called Asian Flushing Syndrome (AFS), affects the enzymes that break down alcohol. It is characterised by facial flushing, headache, nausea and palpitations in response to a small amount of alcohol intake.”

Hair of the dog: the science

“The expression ‘hair of the dog’ is shortened from ‘hair of the dog that bit you’. It comes from the age-old idea that sometimes the cause of an ailment can also be its cure,” explains immunologist, Dr Jenna Macciochi.

“There are no solid scientific studies assessing whether it works, but the theory behind it suggests that because hangover symptoms are a result of your body breaking down alcohol to get rid of it, raising alcohol in the body again by drinking would remove those symptoms.

“It has also been claimed that drinking alcohol boosts endorphins, which can help mask uncomfortable hangover symptoms

“However, when you eventually stop drinking and your blood alcohol levels return to zero, the hangover will return. In some sense, ‘hair of the dog’ delays the time until you experience a hangover – but it cannot prevent it entirely.”

What else can you try?

“Some hangover symptoms are due to dehydration, so drinking plenty of water is important. But it’s not the only factor,” says Dr Macciochi.

“An evening of heavy drinking can lead to inflammation of the stomach and intestines, poor-quality sleep and the production of toxic substances as the alcohol is broken down and removed by your liver.”

Science tells us that eating the right foods, including high-protein ingredients, could help combat this.

This means that the classic morning-after-the-night-before brekkie – a good-old Full English – might actually help.

“Foods rich in an amino acid called cysteine can decrease the amount of the toxic chemical acetaldehyde, which is produced as your body metabolises alcohol. Cysteine is found in most high-protein foods such as red meat, chicken, eggs, turkey, yoghurt, cheese, sunflower seeds and legumes – perhaps this is where the idea of a fry-up comes from.

“For the inflammation, you should aim to stabilise your blood sugars, which can send inflammation crazy. Eat a lot of plant-based fibre and green leafy vegetables the following day. Bone broth, rich in gelatine, can be helpful for this too.”

Some people think supplements might help ease symptoms as well, says Dr Macciochi.

“Alcohol depletes a number of nutrients from the body, but in particular our B vitamins, which are water-soluble (so flushed out by increased urination caused by drinking).”

This is particularly relevant because it’s thought that B vitamins play a key role in helping to metabolise alcohol – as does zinc.

“Taking a B complex and zinc supplement before or after drinking can be beneficial,” suggests Dr Macciochi.

There is also evidence that going back to bed – or having a coffee – could do the trick.

“Because of the poor sleep associated with drinking (even if you feel like you fall into a deep sleep, the quality will be affected), having coffee can overcome some of the tiredness you might feel the next day. But taking a nap is probably best if you can fit it in,” says Dr Macciochi.

Why do we get hangovers, anyway?

“The main cause of a hangover is ethanol – the alcohol in your drinks. It’s a toxic chemical that works in the body as a diuretic, which means it makes you pee more and you can become dehydrated as a result. Dehydration is one of the main causes of your hangover symptoms.

“In addition, chemicals called congeners can also cause more intense hangovers. When you drink, your blood vessels widen. This effect, known as vasodilation, is associated with headaches,” says Dr Macciochi.

It is a commonly held belief that hangovers become worse when we age. While no study has definitively demonstrated this effect, there are several theories about why this may be,” says Dr Owen.

“For example, as a person ages, there tends to be a decline in total body water, intracellular water and muscle mass. This is because there are fewer, and less-hydrated, muscle cells in aged individuals. It may lead to higher blood alcohol concentrations when we drink.”

And as for those who can seemingly drink alcohol without having to face any ill effects the next day, there are lots of potential explanations, says Royle.

“There could be a number of reasons why certain people don’t achieve these ‘thresholds’ for experiencing hangovers, including drinking less, drinking more slowly, or having a biology that enables you to process alcohol quickly.”

Could worrying about your hangover make it worse?

If you’re the kind of person who worries or exaggerates pain, you might face a more severe hangover according to research carried out at University of Salford.

Royle was the lead researcher on a study of 86 participants. “Our results show the more you catastrophising about pain, the more severe a hangover you report, even after we’ve accounted for how much you actually drank.

This is interesting because catastrophic thoughts have been shown to be important in how we respond to pain (if we ‘battle through’ or not). This may suggest a role for catastrophizing in workplace absenteeism caused by hangover, or otherwise lost productivity associated with the experience.”

Originally published December 2019, updated December 2024

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