Do Hangover Cures Work? What 21 Trials Found, and What Actually Sobers You Up (Nothing but Time)

Why do hangovers happen

Alcohol is broken down in two steps. Alcohol dehydrogenase converts it to acetaldehyde, and aldehyde dehydrogenase converts that to acetate. The intermediate, acetaldehyde, is the compound linked to hangover symptoms. How fast that second step runs is partly inherited, and where it stalls the face turns red: the ALDH2 variant behind flushing, and why building a tolerance to it raises the risk rather than lowering it.

The chemistry fits in two sentences. The part that refuses to fit anywhere is a verified way to switch the symptoms off, because no such method has been established.

What did the trials actually find

The reference point is a systematic review by a King's College London team, published in the journal Addiction in December 2021. The researchers gathered every placebo-controlled randomised trial of hangover interventions they could find: 21 trials, 386 participants in total. No two trials tested the same intervention, which made a meta-analysis impossible. Owing to methodological problems and imprecision, every efficacy result was rated very low quality on the GRADE scale, and 8 of the 21 trials enrolled only men.

Some interventions did beat placebo. The list runs clove extract, tolfenamic acid, pyritinol, Hovenia dulcis fruit extract, L-cysteine, red ginseng and Korean pear juice. The authors' conclusion, however, reads differently from the list: the evidence is of very low quality, and not one of those results has been independently replicated.

Two entries on that list, red ginseng and Korean pear juice, are Korea's signature morning-after beliefs, and their presence means both have actually been through clinical trials. Statistically significant, very low certainty, never replicated. Those clauses have to travel together. The first alone is an advertisement; with the second attached, it becomes a fact.

An older review was blunter. The 2005 systematic review in the BMJ concluded that no convincing evidence exists for any intervention, conventional or complementary, that prevents or treats a hangover, and that the most effective way to avoid hangover symptoms is to drink less or abstain.

How do four countries handle it

The cures themselves are folk territory everywhere. What differs is what each system does about the belief.

Table: what each country's shelves actually offer, alongside its regulatory status and level of evidence.

United States: the cure that went to trial

US

Among the interventions in the Addiction review is SJP-001, a combination of naproxen and fexofenadine developed in the United States. It made it into a placebo-controlled trial, which is further than most morning-after ideas ever travel. The result matched everything else in the review: very low certainty evidence.

This section stops there. The regulatory and market side of the American story needs sources we have not yet verified, so it waits.

United Kingdom: funding the question, not the cure

GB

Both reviews this article leans on are British work. The 2022 Addiction paper came from King's College London, part-funded by a National Institute for Health Research biomedical research centre, and the blunter 2005 review ran in the BMJ.

Rather than regulating products or sorting them into legal categories, the UK's visible contribution has been to put public research money into the prior question of whether any of it works. A third kind of response, and this article is a direct beneficiary of it.

South Korea: prove it or drop the claim

KR

Hangover drinks stacked beside the convenience store till are close to standard procedure in Korean drinking culture. Since January 1, 2025, the wording on those bottles comes with a condition: any food labelled or advertised with hangover-relief claims must hold human clinical trial data. The rule covers every phrase that leads a consumer to expect relief from drinking, including "sobers you up" and "for the morning after", and claims must pass review by an industry self-regulation body.

What has to be proven is specific. A 2023 guideline from the food and drug ministry set the endpoints: significant improvement in hangover severity scores, and significant improvement in blood alcohol and blood acetaldehyde concentrations.

The outcome arrived as a number. When the ministry surveyed the market in 2024, 177 products were registered as hangover remedies. By early 2025, 39 companies had produced trial data covering 81 products. The other 96 lost the right to use the claim. Online monitoring began on January 13, 2025, and a company that kept advertising without data received a 15-day business suspension for a first violation.

There is a story inside the drop from 177 to 81. The market grew faster than the evidence, and regulation arrived late to measure the gap. Myth-busting is usually a job for journals; here it was done by enforcement.

One distinction is worth keeping sharp. What the surviving 81 products hold is the trial data the regulation demanded. That is not the same bar as independently replicated evidence, the standard the academic reviews apply.

Japan: one brand, two shelves

JP

The product list of Hepalyse, Japan's flagship hangover brand, doubles as a diagram of the regulatory system. By the manufacturer's own account it sells nine products as foods, six as medicines with stated effects, and one as a quasi-drug. Convenience stores and supermarkets carry the soft drink and dietary supplement lines; pharmacies and drugstores carry the medicines. Stores without a pharmaceutical sales licence are simply not allowed to sell the medicine versions.

The same brand name, a different legal identity depending on the shelf. Where Korea chose to demand proof for a single phrase, what stands out in Japan is a market split down the middle by legal category, distribution channels and all.

Three responses to the same belief: demand proof, split the product, or fund the question. They all start from the same place, the gap between what sells and what has been shown to work.

What you can do

The evidence points in an unexciting direction. The most effective way to avoid hangover symptoms is to drink less or not at all; that was the 2005 conclusion, and the 2022 review found nothing to overturn it. The NIAAA arrives at the same place from the other side: there is no quick cure, only time will help. Watching the amount and pace on drinking days, and keeping days without alcohol. That is, in practice, the whole verified list.

As for drinking water before bed or the restorative morning soup, the sources we reviewed contain no verification either way. That is not the same as proven useless; it means unexamined. The gap gets filled by personal experiment, which is exactly why this topic never stops being discussed.

One thing worth knowing about habits of this kind is that some countries fund help with them and publish the terms. On smoking, the entitlements are written down in detail: which countries pay for counselling and medication, how many attempts a year, and where a treatment app is prescribable.

What does a pattern of hangovers mean

If nothing erases a hangover, a recurring one deserves a different reading. Turn the literature's conclusion around: frequent hangovers are a signal that the drinking is outrunning what your body can process.

If cutting down keeps not happening, talking to a clinician or a professional support service beats another round of private resolutions. One thing to know before the attempt: stopping overnight can be harmful for someone who has become physically dependent, and cutting down counts as a treatment goal in its own right.

When it is an emergency: alcohol overdose

This section is not about hangovers. It is about the night before, and the signs that turn a drinking session into a medical emergency. The US National Institute on Alcohol Abuse and Alcoholism (NIAAA) lists the signs of alcohol overdose: mental confusion, difficulty remaining conscious, vomiting, seizures, trouble breathing, slow heart rate, clammy skin, dulled responses such as a missing gag reflex, and extremely low body temperature. It means blood alcohol has climbed high enough that the brain areas controlling breathing, heart rate and temperature are starting to shut down, and it can end in permanent brain damage or death. If you see these signs, call emergency services immediately.

While waiting, the one useful thing is preventing choking. Lean a vomiting person forward. If they are unconscious or lying down, turn them onto their side with the ear toward the ground so they cannot choke on vomit. That is the entire action list. Nothing in this section sobers anyone up, and no method that claims to has evidence behind it.

The sober-up myths

Step back from the emergency to an ordinary night out, and there is still one list to clear. Of the things said to sober you up fast, none reduces what alcohol is doing to you.

The NIAAA treats coffee as the flagship myth. Caffeine may help with drowsiness, but not with alcohol's effects on decision-making or coordination; the body simply needs time to metabolise the alcohol. And once the caffeine runs out, its own crash lands on top of the alcohol's drowsiness. The institute's own sentence is the verdict this section ends on: there is no quick cure, only time will help.

Judging by appearances is on the myth list too. To the idea that someone who is not slurring or acting strange can drive, the answer given is that the coordination driving requires is impaired well before the visible signs of intoxication appear, and reaction time slows with it.

Restorative soup and sports drinks are not on this list. That means no verified source examined them, not that they were shown useless. Coffee is the one with a clear verdict.

Frequently asked questions

Frequently asked

Is there any hangover cure with solid evidence?

No. The 2022 review rated every result from 21 placebo-controlled trials very low certainty, with no independent replication. The 2005 BMJ review found no convincing evidence for any intervention, conventional or complementary.

What has actually been tested in trials?

Clove extract, tolfenamic acid, pyritinol, Hovenia dulcis fruit extract, L-cysteine, red ginseng and Korean pear juice all showed statistically significant improvement over placebo. Every one of those results sits on very low certainty evidence, and 8 of the 21 trials enrolled only men.

Why can't science settle something this common?

Because the research is scattered thin. Across all 21 trials there were 386 participants, and no two trials tested the same intervention, so results could not be pooled. A question this universal has attracted remarkably little coordinated study.

Does drinking water before bed prevent a hangover?

Not verified in the sources we reviewed, in either direction. The only approach with convincing evidence is drinking less, or not at all.