A typical hangover lasts about 18 hours from your last drink, or roughly 12 hours from the time you wake up. For most people, symptoms fall somewhere in the 14 to 23 hour range, though some hangovers resolve faster and others can stretch up to 24 hours. Several factors, from what you drank to how old you are, determine where you land in that window.
The Hangover Timeline
Hangover symptoms don’t start the moment you stop drinking. They begin creeping in about 8 hours after your last drink, typically while you’re still asleep. Symptoms tend to peak around 14 hours after drinking, which for most people corresponds to early or mid-morning. From there, they gradually fade over the next several hours.
If you stopped drinking at midnight, that means your worst symptoms would hit around 2 p.m. the next day, and you’d likely feel mostly recovered by evening. If you had your last drink at 10 p.m., the peak comes closer to noon. The total arc from first sip of misery to feeling normal again is roughly a full waking day.
Why Symptoms Outlast the Alcohol
One of the confusing things about hangovers is that your blood alcohol level has already dropped to zero before you even start feeling bad. The hangover isn’t caused by alcohol still being in your system. It’s caused by what your body did while processing that alcohol.
When your liver breaks down alcohol, it produces a toxic byproduct called acetaldehyde. This compound is significantly more harmful than alcohol itself. Research on brain tissue has shown that acetaldehyde reduces the ability of cells to produce energy by about 50% and impairs normal oxygen use by around 30%. That kind of cellular disruption in your brain explains the fog, fatigue, and sluggish thinking that define a hangover. Your cells need time to repair that damage even after the acetaldehyde is gone.
There are also effects that operate independently of acetaldehyde. Studies have found that even when acetaldehyde is neutralized, certain types of cellular damage persist, particularly to the proteins that help brain cells communicate with each other. This is part of why hangovers feel so multidimensional: the headache, the nausea, the difficulty concentrating, and the general malaise each involve slightly different recovery processes happening on their own timelines.
What Makes Some Hangovers Last Longer
The biggest factor is simply how much you drank. More alcohol means more acetaldehyde for your liver to clear and more cellular repair work afterward. But several other variables shift the timeline in ways that matter.
Dark vs. Clear Liquor
Darker alcoholic drinks like bourbon, brandy, and red wine contain higher levels of congeners, which are chemical byproducts of fermentation that give these drinks their color and flavor. Congeners add to the toxic load your body has to process, and they’re more likely to produce a hangover or make an existing one worse. Clear liquors like vodka and gin contain far fewer congeners. This doesn’t mean clear spirits are hangover-proof, but they do tend to produce milder aftereffects at the same amount of alcohol.
Age
If hangovers seem to hit harder as you get older, that’s not your imagination. Several things change in your body with age that slow alcohol recovery. The liver enzymes responsible for breaking down alcohol become less efficient over time. Circulation slows, meaning less blood flows through your liver to metabolize toxins, and those toxic byproducts build up for longer.
Your body composition shifts too. You lose roughly 3% to 8% of your lean muscle mass each decade after age 30. Since muscle tissue holds water and helps dilute alcohol in your bloodstream, less muscle means a higher concentration of alcohol from the same number of drinks. On top of that, medications you may be taking for other health conditions compete for the same liver enzymes, further slowing the process. All of this adds up to longer, more intense hangovers from the same amount of drinking that barely affected you at 25.
Hydration, Sleep, and Food
Alcohol is a diuretic, so you lose more fluid than you take in while drinking. Starting a night already dehydrated, or failing to drink water alongside alcohol, extends the recovery period because your body has a deeper deficit to correct. Sleep matters too. Alcohol disrupts sleep quality even when it helps you fall asleep initially, and poor sleep compounds every other hangover symptom. Drinking on an empty stomach accelerates alcohol absorption, which tends to produce a sharper spike in acetaldehyde and a rougher morning.
Why “Hangover Cures” Don’t Work
The supplement industry has no shortage of products claiming to prevent or shorten hangovers. Many of them contain ingredients that sound plausible on paper. L-cysteine, for instance, helps the liver break down acetaldehyde in animal studies, and vitamins B1, B6, and C play roles in cellular repair. But when these ingredients were tested together in a rigorous clinical trial, participants who took the supplement reported no difference in hangover severity compared to those who took a placebo. Their cognitive performance, sleep quality, and blood markers of inflammation were all the same.
Korean pear juice has shown some effect on hangover symptoms, but only in people with specific genetic variations in the enzymes that process acetaldehyde. If you don’t carry those gene variants, it does nothing. This genetic variability is part of why hangover remedies seem to “work” for some people and not others, fueling anecdotal claims that don’t hold up in controlled studies.
What Actually Helps You Recover Faster
There’s no shortcut that eliminates a hangover once it’s started. Your body needs time to repair the cellular damage and rebalance its chemistry. What you can do is avoid making things worse and support the processes already underway.
Rehydrating steadily with water or electrolyte drinks helps your body correct fluid imbalances faster. Eating bland, easy-to-digest food gives your liver the glucose it needs to keep working. Rest matters more than most people give it credit for, since your brain is doing active repair work. Caffeine can temporarily relieve a headache but also adds to dehydration, so it’s a trade-off.
The most reliable way to shorten a hangover is to create a milder one in the first place: drink less, choose lighter-colored drinks, alternate alcoholic beverages with water, eat before and during drinking, and pace yourself to give your liver time to keep up. None of that is exciting advice, but it’s the only approach that consistently changes the math on how you feel the next day.