Do Hard Seltzers Keep You Hydrated? The Truth About Alcohol and Hydration

October 14, 2025 •

3 min read

Despite containing a base of carbonated water, hard seltzers do not actually keep you hydrated due to their alcohol content. This common misconception overlooks the fact that alcohol is a diuretic, which actively promotes fluid loss from the body.

Quick Summary

Hard seltzers are not hydrating because their alcohol content acts as a diuretic, causing increased urination and fluid loss that ultimately leads to dehydration.

Key Points

Alcohol is a diuretic: The alcohol in hard seltzer inhibits the release of vasopressin, causing your kidneys to release more water and leading to fluid loss.
Not a hydrating beverage: Despite being made with a base of carbonated water, the alcohol content in hard seltzers counteracts any hydrating benefits.
Dehydration risk: Consuming hard seltzers, especially in large quantities, increases your risk of dehydration, particularly in hot environments.
Alternate with water: The most effective way to mitigate dehydration is to drink a glass of water for every hard seltzer you consume.
Impact on kidneys: Excessive alcohol intake and the resulting dehydration put a significant strain on your kidneys, which are working to filter waste.
Listen to your body: Pay attention to signs of dehydration like thirst, dry mouth, or fatigue, and increase your water intake accordingly.
Mindful consumption: Moderation is key when drinking hard seltzers to minimize their dehydrating effects and support overall health.

The Deceitful Refreshment: Why Hard Seltzers Are Not Hydrating

Hard seltzers have become widely popular, often seen as a lighter option compared to other alcoholic drinks. Their combination of carbonated water, flavor, and lower calorie count can lead to the false assumption that they contribute to hydration. However, hard seltzers are alcoholic beverages, and alcohol functions as a diuretic, causing the body to lose more fluid than it takes in and leading to dehydration. This effect is particularly noticeable in hot weather or during physical activity.

The Diuretic Effect of Alcohol Explained

Alcohol's dehydrating effect stems from its impact on a hormone called vasopressin (or ADH). Vasopressin normally signals the kidneys to reabsorb water. When alcohol suppresses this hormone's release, the kidneys excrete more water through urination. This increased fluid loss is the reason all alcoholic drinks, including hard seltzers, cause dehydration.

Hard Seltzers vs. Non-Alcoholic Seltzers

There's a significant difference between plain seltzer water and hard seltzer when it comes to hydration. Non-alcoholic seltzer is a good source of hydration, while hard seltzer's alcohol content has a dehydrating effect. Consuming large amounts of hard seltzer can also disrupt electrolyte balance by flushing out minerals like sodium and potassium through increased urination.

A Comparison of Beverage Hydration Effects


Beverage	Alcohol Content	Primary Hydration Effect	Calories (approx.)	Key Consideration
Plain Water	0%	Hydrating	0	The gold standard for hydration.
Plain Seltzer	0%	Hydrating	0	Hydrating and a refreshing, fizzy alternative to plain water.
Hard Seltzer	4–6% ABV	Dehydrating	100	Alcohol content promotes fluid loss via urination.
Light Beer	4–5% ABV	Dehydrating	100–120	Still dehydrating, but with less alcohol content per volume than spirits.
Wine	12–15% ABV	Dehydrating	125	Higher alcohol by volume makes it more dehydrating per serving.
Sports Drink	0%	Hydrating & Electrolyte Replenishing	Variable	Designed to rehydrate and replace electrolytes lost during exercise.

Strategies to Counter Dehydration While Drinking

Since hard seltzers are dehydrating, it's important to take steps to manage hydration when drinking them:

Alternate with water: Drink a glass of water for every hard seltzer to help replace lost fluids and moderate alcohol intake.
Pre-hydrate: Ensure you are well-hydrated before consuming alcohol to avoid starting with a fluid deficit.
Eat food: Eating before or while drinking can slow alcohol absorption and its diuretic effect.
Moderate consumption: The amount and speed of drinking impact dehydration. Practice moderation and pace your intake.
Include hydrating foods: Consume water-rich fruits and vegetables like watermelon or cucumbers.
Rehydrate after drinking: Replenish fluids and electrolytes with water or a sports drink after consuming several hard seltzers.

Potential Health Risks Beyond Dehydration

The dehydration caused by hard seltzers can lead to health issues beyond thirst. The kidneys are stressed by working to filter waste products amidst fluid loss. Chronic dehydration can result in fatigue, headaches, and impaired cognitive function. The carbonation in seltzers might also speed up alcohol absorption, potentially leading to faster intoxication.

Conclusion: Mindful Consumption is Key

Contrary to popular belief, hard seltzers do not keep you hydrated. Their alcohol content acts as a diuretic, promoting fluid loss despite the water base. Therefore, hard seltzers are dehydrating. To enjoy them responsibly, practice moderation and prioritize drinking plenty of water. Treat hard seltzers and other alcoholic drinks as beverages that require careful hydration management, not as hydrating alternatives to water. For more information on kidney health and hydration, you can find resources from the National Kidney Foundation.

Frequently Asked Questions

No, hard seltzers do not count towards your daily water intake because their alcohol content acts as a diuretic, causing a net fluid loss from your body.

The alcohol within hard seltzers is a diuretic. It suppresses the antidiuretic hormone vasopressin, which causes the kidneys to excrete more water than they reabsorb, leading to dehydration.

The hydration effect is poor for both. While the exact degree depends on the alcohol content, all alcoholic beverages are diuretics. The best strategy is to consume either in moderation and supplement with plenty of water.

Common symptoms of dehydration include increased thirst, dry mouth, headaches, fatigue, and dark-colored urine. These can worsen if you are not drinking enough water alongside your alcoholic beverages.

To prevent dehydration, it is recommended to alternate each hard seltzer with a glass of water. Additionally, you should be well-hydrated before you start drinking and eat hydrating foods.

The small amount of electrolytes in some hard seltzers does not counteract the significant diuretic effect of the alcohol. The beverage will still cause dehydration, making it an unreliable source of hydration.

Yes, excessive alcohol consumption and subsequent dehydration put additional strain on the kidneys. Regular heavy drinking can increase the risk of kidney damage over time.