Ah, the dreaded hangover. Whether it’s a pounding headache, bone-deep fatigue, or that “never drinking again” regret, hangovers can ruin even the best mornings.

But why do they last so long — and why do some people feel way worse than others?

Here’s what science (and experience) says about how long hangovers actually last, what causes them, and how to make recovery smoother — especially if you deal with Asian Flush or alcohol sensitivity.

So, What Is a Hangover?

A hangover is your body’s way of saying: “We’re still processing last night.”

When you drink, your body scrambles to detoxify alcohol and rebalance itself. The result? A symphony of symptoms that can include:

• Headaches and nausea
• Fatigue or weakness
• Dehydration and dry mouth
• Sensitivity to light or sound
• Brain fog or irritability

Essentially, it’s not one thing — it’s a full-body recovery mission.

Why Hangovers Happen

There’s no single cause — hangovers are the result of several overlapping processes.

1. Acetaldehyde Overload

When alcohol breaks down, it first becomes acetaldehyde — a toxic, inflammatory by-product that can cause redness, nausea, and headaches.

If your body can’t clear acetaldehyde efficiently (especially if you have an ALDH2 enzyme deficiency), symptoms hit harder and last longer.

2. Dehydration

Alcohol is a diuretic — it tells your kidneys to flush out more water than usual.
That’s why you wake up dry-mouthed, thirsty, and dizzy.

3. Inflammation

Alcohol triggers your immune system, leading to fatigue, headaches, and that “hungover anxiety” (yes, that’s real).

4. Sleep Disruption

Even if you pass out fast, alcohol messes with REM sleep, leaving you groggy and foggy the next day.

How Long Do Hangovers Last?

Most hangovers last between 8 and 24 hours, depending on:

• How much you drank
• What you drank (dark liquors cause worse hangovers)
• How hydrated and nourished you were
• How well your body processes alcohol

Mild hangovers may fade by lunchtime. But if you drank heavily or metabolise alcohol slowly (as with Asian Flush), symptoms can linger for up to 36 hours.

Why Some People Feel Worse Than Others

Genetics

If you have ALDH2 deficiency, your body struggles to clear acetaldehyde — the main toxin behind redness, nausea, and fatigue. That means more inflammation and a longer recovery window.

Alcohol Type

Dark liquors like whiskey, rum, and red wine contain congeners — fermentation by-products that intensify headaches and nausea.

Hydration & Nutrition

Drinking on an empty stomach or skipping water accelerates alcohol absorption and worsens dehydration.

Sleep Quality

You may “sleep deeply” after drinking, but it’s poor-quality rest — your brain never hits full recovery mode.

The Typical Hangover Timeline

0–6 hours after your last drink:
Dehydration starts. Fatigue and nausea creep in as your body begins breaking down alcohol.

6–12 hours:
Acetaldehyde peaks. Headaches, dizziness, and inflammation make this the worst stretch.

12–24 hours:
Your body’s in repair mode — flushing toxins, rehydrating, and trying to rebalance hormones. Fatigue and brain fog linger.

24+ hours:
Most symptoms ease, but low mood and poor concentration can last into the next day.

How to Recover Faster

1. Rehydrate — But Smarter

Water helps, but electrolytes help more. Replace sodium, magnesium, and potassium lost through increased urination.

2. Eat the Right Foods

Choose nutrient-rich foods like eggs, bananas, and leafy greens — they replenish vitamins B and C and support liver enzymes.

3. Rest and Reset

Sleep is your body’s best repair tool. Aim for a full night of uninterrupted rest — ideally with no alarms.

4. Support Your Detox Pathways

Hydration helps thirst, but it won’t clear acetaldehyde — that’s your enzymes’ job.

That’s where iBlush comes in. Our science-backed formulas use antioxidants like Glutathione, N-Acetyl Cysteine (NAC), and R-Alpha Lipoic Acid (R-ALA) to help your body process alcohol by-products more efficiently — reducing the redness, nausea, and lingering fog.

💡 In short: water helps your thirst; iBlush helps your recovery.

Prevention Tips That Actually Work

• Eat before drinking — it slows absorption.
• Alternate alcohol with water or electrolyte drinks.
• Stick to lighter drinks with fewer congeners.
• Prioritise real sleep, not “passing out.”
• Take iBlush before drinking — support your body before symptoms start.

The Bottom Line

Hangovers aren’t just dehydration — they’re your body dealing with acetaldehyde, inflammation, and disrupted sleep.

For most people, they fade within a day. But for those with Asian Flush or slower alcohol metabolism, they can stick around much longer.

Hydrate smart, rest well, and support your body with antioxidants.
Because mornings after shouldn’t feel like punishment.

P.S. We did the research so you don't have to:

1. National Institute on Alcohol Abuse and Alcoholism (NIAAA). Alcohol Flush Reaction – Does Drinking Alcohol Make Your Face Red? National Institutes of Health, U.S. Department of Health and Human Services.
2. Brooks, P. J., Enoch, M. A., Goldman, D., Li, T. K., & Yokoyama, A. (2009). The Alcohol Flushing Response: An Unrecognized Risk Factor for Esophageal Cancer from Alcohol Consumption. PLOS Medicine.
3. Annals Academy of Medicine Singapore. (2023). Association Between Alcohol Flushing Syndrome and Cancer: A Systematic Review and Meta-Analysis. Annals Academy of Medicine Singapore
4. Eriksson, C. J. P. (1982). The Role of Acetaldehyde in the Actions of Alcohol (Update 1982). Alcoholism: Clinical and Experimental Research.