How to treat hangovers

January 6, 2026

The main idea: Drink ORS

Much of the pain of a hangover is caused by dehydration. To treat dehydration, you should drink oral rehydration solution (ORS) instead of plain water.

ORS is water with added glucose and electrolytes to improve fluid absorption and retention. It can taste surprisingly salty at first, but you get used to it quickly.

You can buy pre-mixed packets or make a similar recipe at home.

ORS is also useful for treating dehydration from other causes, like intense exercise or diarrhea.

How it works

The biggest misconception people have about dehydration is that drinking water is always an effective treatment.1

Instead, the body needs electrolytes (and ideally glucose) to effectively absorb and retain water. This fact is not obvious at all, and the path that humanity took to discover this knowledge is long and torturous.

This idea makes more sense when we consider that water in the body usually moves around via osmosis. To control the flow of water, the body pumps electrolytes across semi-permeable membranes, and water follows. Without enough electrolytes to pump, the body can’t control the flow of water, and drinking more water is useless.

In typical day-to-day life, drinking plain water effectively rehydrates you because you’ve usually recently had a nutritious meal full of electrolytes and carbohydrates. But when you’re drinking, you often go long periods without eating and participate in activities that result in heavy electrolyte losses via sweat, vomit, or diarrhea.

The main electrolytes that can be depleted after a night of drinking are sodium, potassium, and chloride. All of these electrolytes are typically absent from alcoholic drinks and can’t be stored long-term in the body.2 ORS is able to rehydrate more effectively than plain water by also supplying these electrolytes.

What’s in ORS

The World Health Organization calls for ORS to have the following composition:

  • Sodium (75 mmol/L), chloride (65 mmol/L), and potassium (20 mmol/L). These are the three electrolytes mentioned above. Sodium, as the dominant electrolyte in the extracellular fluid, is the most important.
  • Glucose (75 mmol/L). Glucose is not an electrolyte, but its presence greatly accelerates sodium absorption. Most digestion and nutrient absorption occurs in the small intestine, which has two mechanisms to absorb sodium: SGLT1 and electroneutral NaCl absorption. SGLT1 requires glucose to function. (In cholera, the electroneutral route is disabled by bacterial toxins, so SGLT1-mediated sodium absorption becomes absolutely critical.)
  • Citrate (10 mmol/L). This solute corrects the acidosis that can occur as a result of diarrhea and dehydration.

This recipe results in a hypotonic fluid with a total osmolality of 245 mOsm/L (below the 290 mOsm/L of blood and extracellular fluid). Hypotonicity helps drive osmotic absorption of water in the intestine.

Comparison to alternatives

In my personal testing of hangover treatments, I’ve found ORS to be the best, Pedialyte to be quite good, Liquid IV to be decent, and Gatorade and water to be terrible.

It’s not hard to see why if we compare their respective sugar and electrolyte concentrations. Keep in mind that the goal is to have enough sodium and glucose to drive SGLT1, while keeping the overall solute concentration low to facilitate the ensuing osmosis.

Fluid Sodium (g/L) Potassium (g/L) Chloride (g/L) Sugar (g/L)
ORS 1.7 0.8 2.3 14
Pedialyte 1.1 0.8 1.2 13
Liquid IV3 1.1 0.8 1.4 23
Gatorade3 0.5 0.1 0.4 58
Water 0 0 0 0
Seawater 11 0.4 19 0

Other techniques

When it comes to hangovers, dehydration isn’t the whole story. Other contributors include:

  • Poor sleep. Alcohol fragments sleep. I’ve found that drinking ORS before bed helps avoid waking up thirsty, but I haven’t found a way to alleviate alcohol’s impact on sleep quality.
  • Acetaldehyde. During metabolism, alcohol is oxidized to acetaldehyde by the enzyme ADH and then to acetate by ALDH. The intermediate product, acetaldehyde, is toxic.4 I have heard good things about ZBiotics, a probiotic that supposedly helps your body break down acetaldehyde, but I haven’t tested it myself.
  • Inflammation. Advil and Tylenol can help, but both come with potential downsides. Advil can irritate the stomach, and Tylenol can overwhelm an already-loaded liver.
  • Gastritis. Antacids would be the obvious treatment, but I don’t have experience with them in this context.

  1. You can even find examples of this misconception in the academic literature! “Alcohol hangover versus dehydration revisited” (link) claims that “A popular theory suggests that dehydration is the primary cause of alcohol hangover and that the consumption of water could alleviate hangover symptoms.” I think the first part is true, but the second part is false. ↩︎

  2. Calcium, magnesium, and phosphate are also electrolytes, but the body naturally has large stores of them (e.g. in bones). Deficiencies in these electrolytes are more likely to be caused by long-term issues like malnutrition than by a night of drinking. ↩︎

  3. Liquid IV and Gatorade are a little hard to compare to the others because they supply some of their sugar as sucrose, whereas ORS and Pedialyte only have glucose. SGLT1 specifically requires glucose to function, but sucrose is a disaccharide that can be broken down into glucose and fructose. For the purposes of rehydration, the difference is probably small. ↩︎ ↩︎

  4. People with the ALDH2 mutation (common in East Asians) are less efficient at processing acetaldehyde and experience “alcohol flush”. ↩︎