Part of our Asian Flush & Alcohol guide library.
Short answer: A hangover usually peaks when your blood alcohol level drops back to about zero, often the morning after drinking, and the symptoms can last 24 hours or longer. No hangover remedy has solid scientific evidence behind it: reviews of randomized trials found only very low quality evidence for any pill or supplement. Only time makes a hangover go away. Rest, water and skipping more alcohol can help you feel more comfortable while your body recovers. Be careful with pain relievers, and get emergency help for signs of alcohol poisoning.
Pounding head, upset stomach, no energy: if you are reading this the morning after, you probably want two answers fast. How long will this last, and what will make it better? Here is what the U.S. National Institute on Alcohol Abuse and Alcoholism (NIAAA) and the research say, including which popular fixes do not work and when a hangover is actually something more serious.
What you'll learn
- How long a hangover lasts and when it peaks
- What causes hangover symptoms
- What actually helps, and what does not
- Pain reliever cautions and when to get emergency help
How long does a hangover last?
Hangover symptoms peak when the alcohol concentration in your blood returns to about zero, and they can last 24 hours or longer (NIAAA). In practice, that often means feeling worst the morning after a night of drinking. How long yours lasts depends on how much you drank and on you: hangovers vary from person to person, and it is hard to predict how many drinks will cause one (NIAAA). In general, the more alcohol you drink, the worse the hangover (NIAAA).
Common hangover symptoms
Typical symptoms include fatigue, weakness, thirst, headache, muscle aches, nausea, stomach pain, dizziness or vertigo, sensitivity to light and sound, anxiety, irritability, sweating and increased blood pressure (NIAAA). A hangover can also affect your attention, decision-making and coordination, so it can make driving, operating machinery or caring for others unsafe (NIAAA).
What causes a hangover?
Several things happen at once (NIAAA):
| Cause | What happens |
|---|---|
| Mild dehydration | Alcohol suppresses vasopressin, a hormone that tells your kidneys to hold on to fluid, so you urinate more |
| Disrupted sleep | You may fall asleep faster, but sleep is fragmented and you tend to wake up earlier |
| Stomach irritation | Alcohol irritates the stomach lining and increases acid release, causing nausea and discomfort |
| Inflammation | Alcohol increases inflammation in the body, which may add to the sick, run-down feeling |
| Acetaldehyde | Breaking down alcohol creates acetaldehyde, a toxic, short-lived byproduct |
| Mini-withdrawal | As the buzz wears off, you can feel more restless and anxious than before you drank |
Other ingredients matter too. Congeners, compounds made during fermentation, are higher in darker spirits such as bourbon and could worsen hangovers for some people, and people sensitive to sulfites may get a headache from wine (NIAAA). If your face turns red when you drink, acetaldehyde may be building up faster than your body can clear it; see why some people get Asian flush.
What actually helps a hangover?
The honest answer is time. According to NIAAA, none of the many hangover remedies promoted online has been shown by science to be effective, and only time helps: your body has to clear the byproducts of alcohol, rehydrate, heal irritated tissue and bring immune and brain activity back to normal (NIAAA).
The research agrees. A 2022 systematic review of 21 placebo-controlled trials with 386 participants found that no two studies tested the same remedy, and all of the evidence was very low quality, so no pill or supplement can be recommended (Roberts et al., 2022). An earlier review in the BMJ found no compelling evidence that any conventional or complementary remedy prevents or treats hangover (Pittler et al., 2005).
While you wait it out, these simple steps can make you more comfortable:
- Rest. Alcohol fragments sleep (NIAAA), so extra rest helps with fatigue.
- Drink water. Mild dehydration likely contributes to thirst, fatigue and headache (NIAAA).
- Do not drink more alcohol. A "hair of the dog" may briefly mask symptoms but can prolong the hangover (NIAAA).
- Avoid driving or other tasks that need full attention until you feel normal (NIAAA).
Hangover myths
NIAAA lists several common beliefs that do not hold up (NIAAA):
| Myth | What the evidence says |
|---|---|
| Coffee or a cold shower will fix it | Nothing speeds up the brain's recovery from alcohol; only time helps |
| "Beer before liquor, never sicker" | The order does not matter much; the total amount of alcohol does |
| A morning drink (hair of the dog) helps | It may briefly ease symptoms but can prolong the hangover |
| Electrolyte drinks or IV drips fix it | Research has not found a link between electrolyte changes and how bad a hangover is, or that added electrolytes reduce it |
If you drink coffee every day, a cup can still be part of your normal routine, and skipping it may add a caffeine withdrawal headache on top; see caffeine withdrawal. Just do not expect it to end the hangover.
Be careful with pain relievers
Some people take a pain reliever, often acetaminophen (Tylenol), at bedtime to head off a hangover, but alcohol and acetaminophen together can be toxic to the liver. Aspirin and ibuprofen can increase acid release and irritate the stomach lining, as alcohol does (NIAAA). Ask a pharmacist before taking any pain reliever around drinking, especially if you have liver, kidney or stomach problems or take other medicines.
Hangover or alcohol poisoning?
A hangover is miserable but passes. Alcohol poisoning (overdose) is an emergency. Call 911 right away if someone who has been drinking shows any of these signs (NIAAA):
- Confusion or stupor, or trouble staying conscious or cannot be woken
- Vomiting
- Seizures
- Slow breathing (fewer than 8 breaths a minute) or irregular breathing (10 seconds or more between breaths)
- Slow heart rate, clammy skin, or no gag reflex
- Very low body temperature, bluish skin or paleness
Do not wait for all of the signs. Cold showers, hot coffee and walking do not reverse an alcohol overdose and can make things worse (NIAAA).
How to prevent a hangover next time
The only sure way to avoid a hangover is not to drink, or to keep alcohol to a minimum (NIAAA). If you do drink:
- Count standard drinks. One U.S. standard drink has about 14 grams of alcohol: 12 ounces of 5% beer, 5 ounces of 12% wine or 1.5 ounces of 40% spirits (NIAAA).
- Pace yourself and alternate alcoholic drinks with water or an alcohol-free option.
- Choose lighter drinks if darker spirits or wine tend to hit you harder (NIAAA).
- Plan your ride home before you start.
For a full before, during and after checklist, see how to prevent Asian flush, and for an alcohol-free drink to bring along, try our Mango Sunset Spritz (make the alcohol-free version).
Common myths (quick reality check)
Myth: A hangover goes away by lunchtime. Reality: Symptoms peak when blood alcohol returns to about zero and can last 24 hours or longer.
Myth: Some remedies reliably stop a hangover. Reality: Reviews of randomized trials found only very low quality evidence for any remedy. Only time makes a hangover go away.
Myth: Taking Tylenol before bed prevents a hangover. Reality: Alcohol and acetaminophen together can be toxic to the liver, so this is not a safe habit.
Frequently asked questions (FAQ)
How long does a hangover last?
Symptoms peak when your blood alcohol level returns to about zero, often the morning after, and can last 24 hours or longer.
How long can a hangover last?
Usually up to about a day, and sometimes longer. If symptoms are severe or include confusion, vomiting, seizures or slow breathing, get emergency help.
What helps a hangover?
Only time makes it go away, but rest, water and avoiding more alcohol can make you more comfortable.
Does coffee help a hangover?
Coffee does not end a hangover. If you drink it daily, a usual cup may prevent a caffeine withdrawal headache from adding to your symptoms.
Do electrolyte drinks help a hangover?
Research has not found that electrolyte changes match hangover severity or that added electrolytes reduce symptoms. Water is fine for most people.
Can I take a pain reliever for a hangover?
Be careful. Acetaminophen with alcohol can harm the liver, and aspirin and ibuprofen can irritate the stomach. Ask a pharmacist first.
Related guides
- How to prevent Asian flush
- Why do Asians get Asian flush?
- Alcohol intolerance vs alcohol allergy
- Alcohol and liver disease
- The complete guide to Asian flush
Disclaimer and when to seek help
This article is for general education and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease. If someone shows signs of alcohol poisoning, call 911. Talk to your health care provider if you are concerned about your drinking, have liver, kidney or stomach problems, are pregnant, or take medication.
References
- National Institute on Alcohol Abuse and Alcoholism. "Hangovers".
- National Institute on Alcohol Abuse and Alcoholism. "Understanding the Dangers of Alcohol Overdose".
- National Institute on Alcohol Abuse and Alcoholism. "What Is A Standard Drink?".
- 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;117(8):2157-2167. doi:10.1111/add.15786
- Pittler MH, Verster JC, Ernst E. "Interventions for preventing or treating alcohol hangover: systematic review of randomised controlled trials." BMJ, 2005;331(7531):1515-1518. doi:10.1136/bmj.331.7531.1515
