Hangovers and Congeners: Does the Drink Matter?

Bourbon left drinkers feeling worse than vodka in a controlled trial. Yet both impaired next-day attention and reaction to a comparable degree.[2] Does the drink matter, then? For how rough the morning feels, it can. But the amount of alcohol matters more.

A review by Rohsenow and Howland found that ethanol, the alcohol in drinks, had a considerably stronger effect on hangover than congeners, the other compounds found alongside it.[1] Clear spirits are not a way around this: the Alcohol Hangover Research Group concludes that ethanol alone is sufficient to produce a hangover.[3]

What happens during a hangover?

A hangover can mean fatigue, weakness, nausea, dizziness, sensitivity to light and sound, anxiety and more, not simply thirst or a headache. The US National Institute on Alcohol Abuse and Alcoholism (NIAAA) says symptoms typically peak when blood alcohol returns to about zero and can last 24 hours or longer.[6]

Researchers have also changed how they define the experience. In 2020, Verster and colleagues defined hangover as “negative mental and physical symptoms which can be experienced after a single episode of alcohol consumption”, removing the earlier definition’s requirement for heavy drinking.[4]

Several processes may contribute. NIAAA describes how alcohol disrupts sleep, irritates the stomach lining and increases acid release. It also increases inflammation, which may contribute to symptoms. Its breakdown produces acetaldehyde, a toxic, short-lived by-product.[6]

NIAAA also describes a “mini-withdrawal” as alcohol’s effects wear off, involving restlessness and anxiety.[6] The next morning’s discomfort can therefore be mental as well as physical, although hangover does not explain every symptom after drinking.

Hangovers and congeners: what does the evidence show?

Congeners are the compounds alongside ethanol in alcoholic drinks. Swift and Davidson’s review explains that they arise during fermentation, form during ageing or processing, or are added during production. The Alcohol Hangover Research Group’s consensus statement lists methanol, esters, acetaldehydes, tannins and fusel oil among them.[7][3]

They are a varied group, not interchangeable substances with one shared effect. The consensus statement says congeners may worsen hangover severity. NIAAA adds that darker spirits such as bourbon tend to contain more and could worsen symptoms for some people.[3][6]

The clearest comparison in this research puts bourbon beside vodka. An ATTC Network summary of Rohsenow and colleagues’ 2010 study reports that 95 healthy heavy drinkers received bourbon or vodka, with a matched placebo night. The bourbon contained 37 times as many congeners as the vodka.[2]

Bourbon and vodka trial verdict

The wider review by Rohsenow and Howland puts congeners in perspective: ethanol had the considerably stronger effect. With only a small number of studies available, the authors called for more research.[1] Congeners matter, but the evidence does not make them the main explanation for hangover.

Does every whisky have the same congener content?

No. Whisky is not one chemically uniform category. The 2010 consensus statement reports wide variation between whisky types, including bourbon containing more than three times as much total congeners by weight as Canadian whisky.[3] That comparison establishes a difference between the whisky types described, not a ranking of every style or individual bottle.

Whisky congener comparison verdict

The bourbon-versus-vodka experiment does not make a drink’s appearance a dependable guide to someone’s next morning.

NIAAA’s broader finding remains the more useful guide: the more alcohol consumed, the worse the hangover, regardless of whether it comes from beer, wine, distilled spirits or a combination.[6] For comparing amounts rather than drink names, see alcohol units and drinking guidelines.

Does drinking order make a difference?

“Beer before wine” offered no advantage in the trial described by Köchling and colleagues. As reported by Live Science, 90 volunteers aged 19 to 40 received beer followed by wine, wine followed by beer, or one drink type. Hangover scores were similar across the groups.[11]

Perceived drunkenness and vomiting predicted hangover severity, rather than drinking order.[11] This is evidence against the saying, not evidence that mixing drinks is harmless: NIAAA identifies the amount of alcohol as the more important factor.[6]

Beer before wine verdict

Water, dehydration and electrolyte drinks

Dehydration does not explain the whole hangover. The sources differ, however, on how much it contributes.

NIAAA says alcohol suppresses vasopressin, increasing fluid loss, and that the resulting mild dehydration “likely contributes” to thirst, fatigue and headache.[6] NHS 111 Wales advises rehydrating, while a 2024 paper in Alcohol: Clinical and Experimental Research states that hangover “is not caused by dehydration” and that drinking water does not prevent it.[10][12]

These are distinct accounts, not a settled explanation. NIAAA also reports that research has found no connection between the extent of electrolyte disruption and hangover severity.[6] Its account does not establish electrolyte drinks as a hangover treatment.

Are there proven hangover remedies?

No remedy has convincing support from these evidence reviews. Pittler, Verster and Ernst’s 2005 systematic review examined eight randomised trials of eight treatments and found “No compelling evidence” that any intervention prevented or treated hangover.[8]

The later review by Roberts and colleagues, published in 2022, included 21 studies with 386 participants. It found only very low quality evidence for any remedy; identifying substances that might warrant further study was not a recommendation to use them.[9]

“Studied” is not the same as effective. An ingredient’s inclusion in a controlled trial does not demonstrate that it works, and repeating a finding from a small evidence base does not turn it into an established treatment.[9]

NIAAA says there is no magic remedy and that only time cures a hangover. Coffee and showers do not provide the cure sometimes claimed for them.[6] The 2005 review identified abstinence or moderation as the most effective approach to avoiding hangover, rather than a treatment taken afterwards.[8]

What about painkillers?

The official sources checked give differing advice. NHS 111 Wales prefers paracetamol-based remedies to aspirin, while NIAAA warns that alcohol combined with acetaminophen, the US name for paracetamol, “can be toxic to the liver”.[10][6]

This disagreement does not support a painkiller recommendation here. The sources should not be combined into a general instruction to take one after drinking; see alcohol and medicines for the separate subject of interaction risks.

Hair of the dog: does another drink help?

NIAAA calls the idea that another alcoholic drink cures a hangover a myth and says it may prolong symptoms.[6] A proposed explanation for temporary relief does not make it a cure.

Swift and Davidson describe how ethanol slows the body’s breakdown of methanol. Their review discusses methanol as a possible contributor to hangover, but that mechanism does not demonstrate that drinking again treats it.[7]

Legend verdict

Feeling better is not a performance test

The bourbon and vodka study gives a particularly useful warning: participants did not recognise their next-day impairment and believed their driving ability was unaffected.[2] Feeling less unwell after a particular drink therefore did not mean normal attention and reaction had returned. The only safe amount of alcohol before driving is none.

NIAAA’s account also places the peak of hangover symptoms around the time blood alcohol returns to zero.[6] The end of intoxication and the end of next-day effects should not be treated as the same event.

Where to go next

• Whisky and Health: What the Evidence Says: the wider evidence beyond next-day symptoms.
• Alcohol Dependence and Where to Get Help: information about dependence and sources of support.
• Drink Driving Limits Around the World: the separate legal and safety questions around driving.

Sources

1. Rohsenow DJ, Howland J. The role of beverage congeners in hangover and other residual effects of alcohol intoxication: a review. Current Drug Abuse Reviews, 2010. https://pubmed.ncbi.nlm.nih.gov/20712591/
2. ATTC Network. Darker Color Drinks Worse the Next Day. Undated summary of Rohsenow and colleagues’ study in Alcoholism: Clinical and Experimental Research, March 2010, 34(3), pages 509 to 518. https://attcnetwork.org/asme_articles/darker-color-drinks-worse-next-day/
3. Verster JC and colleagues. The Alcohol Hangover Research Group Consensus Statement on Best Practice in Alcohol Hangover Research. Current Drug Abuse Reviews, 2010. https://pmc.ncbi.nlm.nih.gov/articles/PMC3827719/
4. Verster JC, Scholey A, van de Loo AJAE, Benson S, Stock AK. Updating the Definition of the Alcohol Hangover. Journal of Clinical Medicine, 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC7141232/
5. National Institute on Alcohol Abuse and Alcoholism. Hangovers. Fact sheet, updated March 2021. https://www.niaaa.nih.gov/sites/default/files/Hangovers.pdf
6. Swift R, Davidson D. Alcohol Hangover: Mechanisms and Mediators. Alcohol Health and Research World, 1998. https://pmc.ncbi.nlm.nih.gov/articles/PMC6761819/
7. Pittler MH, Verster JC, Ernst E. Interventions for preventing or treating alcohol hangover: systematic review of randomised controlled trials. BMJ, 24 December 2005. https://pubmed.ncbi.nlm.nih.gov/16373736/
8. Roberts E, Smith R, Hotopf M, Drummond C. The efficacy and tolerability of pharmacologically active interventions for alcohol-induced hangover symptomatology: a systematic review of the evidence from randomised placebo-controlled trials. Addiction, 2022. https://pubmed.ncbi.nlm.nih.gov/34972259/
9. NHS 111 Wales. Caring For Yourself. Undated web guidance, edition supplied in the verified fact sheet. https://111.wales.nhs.uk/LiveWell/CaringForYourself/
10. Live Science. No, Drinking 'Beer Before Wine' Won't Prevent a Hangover, Study Finds. 2019, secondary report of Köchling and colleagues’ February 2019 trial. https://www.livescience.com/64722-beer-wine-alcohol-order-hangover.html
11. Alcohol: Clinical and Experimental Research. Alcohol hangovers as a predictor of the development of immune-related chronic diseases. 2024. https://onlinelibrary.wiley.com/doi/10.1111/acer.15434

This desk-researched article uses verified fact sheet TOP-A636, distinguishing health authority guidance, research reviews and secondary reports of individual studies.

Last checked: November 2026