Does Coffee Dehydrate You?

crazy by Editorial Staff | Updated on April 26th, 2023

Ever wonder why you must go to the bathroom more when drinking coffee? You do not imagine it – coffee does make you need to pee more frequently.

Find out why in this blog post! We’ll explore the science behind coffee’s diuretic effects and learn to stay hydrated while enjoying your favorite coffee cup.

Executive hands holding water glass using laptop at office

Does caffeine cause dehydration?

Caffeine is a diuretic that increases the amount of urine you produce. This can lead to dehydration if you don’t drink enough fluids. Some studies have found that caffeine can cause people to pass up more urine than normal, although this is usually only in response to very large doses of caffeine.

But research shows that the amount of water lost due to caffeine is very small and that the effect of caffeine on water loss is minor. Moderate caffeine intake has been shown to have no significant impact on overall hydration status. We’ll get into this later.

However, excessive amounts of caffeine may increase water loss. Therefore, it’s important to keep your caffeine intake in moderation and drink plenty of fluids to ensure proper hydration.

The reason why coffee might dehydrate you

Coffee contains caffeine, a diuretic compound that can increase urination frequency. 

Triggers kidneys to flush extra sodium and water from the body

Caffeine is a mild diuretic, which means it causes your kidneys to flush extra sodium and water from the body, but a moderate intake of coffee should not lead to dehydration in healthy people. 

However, very large doses of caffeine are known to increase the blood flow to the kidneys and inhibit sodium absorption, which explains why it can lead to dehydration. 

Some coffee may have higher caffeine content

The caffeine content in coffee is not high enough to cause dehydration. However, certain coffee beans and types have a higher caffeine content that can lead to dehydration if consumed in large quantities. Therefore, it is important to practice moderation when drinking coffee and stay hydrated by drinking plenty of water throughout the day.

Research on coffee and dehydration

There are varying opinions when it comes to the effect of coffee on dehydration.

In 1928, a study was conducted that saw participants excreting up to 50% more urine after consuming large doses of caffeine, suggesting an increased risk for dehydration. 

Despite this study, more recent research has suggested that when moderate amounts of coffee and other caffeinated beverages are consumed alongside water intake, there is no risk for dehydration. In addition, studies have shown that moderate caffeine intake, such as one to three cups of coffee per day, does not lead to dehydration. 

EFSA also concluded that caffeine does not affect hydration status. While research shows that coffee can have a short-term diuretic effect, it is not necessarily dehydrating, meaning it can be consumed in moderation as part of a healthy and balanced diet.

A 2014 study also found that men who consumed caffeinated water after two months of abstaining from both coffee and tea had the same volume of urine output as those who did not consume caffeine. This finding indicates that caffeine does not have a dehydrating effect in this case.

This contrasts the 1928 study, which concluded that coffee could increase urination frequency and lead to dehydration. However, this outdated finding has since been debunked by more recent research.

However, it is important to note that drinking large amounts of coffee can increase fluid loss and thus lead to dehydration. Therefore, monitoring how much caffeine is consumed and staying aware of how it impacts the body is important.

How much caffeine is too much?

The amount of caffeine you should consume depends on factors such as age, weight, and other health conditions that may influence your body’s response to the stimulant.  Excessive caffeine consumption can lead to dehydration and other health issues, so staying within the recommended limits is best.

Generally speaking, the American Academy of Pediatrics recommends that adolescents aged 12 to 18 limit their caffeine intake to no more than 100 mg per day. The Mayo Clinic suggests consuming no more than 400 mg of caffeine daily for adults.

This equals about 4 cups of coffee or 10 cans of caffeinated soda daily. It is important to remember that different beverages contain different amounts of caffeine, so it is best to read labels carefully and keep track of your daily intake.

Coffee and dehydration: the verdict

The verdict on coffee and dehydration is mixed. The research above suggests that caffeine can have a diuretic effect, but the effects may depend on the individual and how much caffeine is consumed. In most cases, it is safe to consume coffee in moderation as part of a healthy hydration plan.

People already dehydrated should limit their caffeine intake and drink plenty of water throughout the day. For those concerned about their hydration levels, switching to decaffeinated coffee or other hydrating beverages, such as herbal teas, maybe a better choice.

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Disclosure: No compensation or free products were received in exchange for writing this review.


Editorial Staff

The editorial staff at Crazy Coffee Crave is a team of coffee enthusiasts & Baristas who enjoy the one thing we all think about as soon as we get up in the morning. Trusted by thousands of readers worldwide.