What Does Caffeinated Water Do?

  • Medical Reviewer: Dany Paul Baby, MD
Medically Reviewed on 9/26/2022

What does caffeinated water do?

Caffeinated water provides water and caffeine. Caffeine increases alertness, mood, and energy and decreases pain as an anti-inflammatory.
Caffeinated water provides water and caffeine. Caffeine increases alertness, mood, and energy and decreases pain as an anti-inflammatory.

Caffeinated water has been around for years. Caffeinated water can be plain or with added flavors and color. Plain caffeinated water tastes like water and has no calories or other nutrients. It provides the effects of caffeine without affecting your diet plan. Caffeine is a stimulant and makes you alert, but it is also a diuretic and is suspected of causing dehydration. What does caffeinated water do, and should you drink it? 

Caffeinated water provides water and caffeine. You get the caffeine along with lots of water and without the sugar, cream, milk, and other nutrients present in coffee, tea, sodas, and energy drinks. There's no set formula for caffeinated water. Different brands contain variable amounts.

Your body needs water for many purposes, including maintaining blood pressure and heart health, removing waste products and toxins through the kidneys, and maintaining brain function, muscle strength, and joint movements. Caffeinated water is one form of liquid intake to meet your fluid requirements.

You need 1.5 to 2.5 liters (6 to 10 cups) of fluid a day. You may need more in hot weather or when exercising or working hard. Your fluid intake can be water, tea, coffee, fruit juices and squashes, and other liquids.

Caffeine is a psychoactive drug. It enhances alertness, arousal, mood, and energy. It counteracts drowsiness and keeps you awake if you are sleepy during a task. Caffeine also reduces appetite and is used in weight-loss plans.

Caffeine also helps in pain relief. It has anti-inflammatory activity and is an ingredient in many pain-relieving products. Caffeine increases the benefit of pain reliever medicines by up to 40%.

Caffeine has several other benefits for long-term health. Regular caffeine intake slows the age-related reduction in mental function, reduces some nervous system disorders, and may increase longevity.

Is caffeinated water safe?

There is no fixed formula for caffeinated water. Most brands contain 3 to 6 milligrams per ounce (10 to 20 milligrams per 100 ml). Consuming 250 milligrams or more of caffeine at one time can cause caffeine intoxication. It would be hard to drink enough caffeinated water to cause toxicity. But you should read the label of the caffeinated water you're buying to be sure you're not getting a more concentrated product.

Caffeinated water is safer than other caffeinated beverages for your teeth. Most sodas are acidic and wear down your enamel. Beverages with sugar and milk have a similar effect. Enamel erosion leads to cavities, tooth decay, and gum disease. Unlike tea and coffee, caffeinated drinks have no tannin that discolors your teeth.

How much caffeine is safe?

The recommended safe limit for healthy adults is 400 milligrams of caffeine a day. This includes caffeine from all sources, including caffeinated water, tea, coffee, sodas, chocolate, energy drinks, and others. Adolescents 12 to 18 should have no more than 100 milligrams a day. Children under 12 should not have food or drink containing caffeine. Pregnant women should have no more than 200 milligrams of caffeine a day.

Consuming more than 250 milligrams of caffeine at once is dangerous and can cause caffeine intoxication. The symptoms are a flushed face, frequent urination, restlessness, nervousness, excitement, muscle twitching, rambling flow of thought and speech, fast heartbeat, and inability to sleep. This usually happens from consuming concentrated liquid or powdered caffeine. Caffeinated water has a low concentration of caffeine and is unlikely to cause such effects.

Is caffeine addictive? Your body can get used to caffeine. If you've been consuming it regularly and stop abruptly, you might suffer from caffeine withdrawal. This can consist of headache, inability to concentrate, irritability, depressed mood, and tiredness.

Dangers of caffeine

Drinking coffee increases blood pressure, but this effect is usually short-lived. If you drink caffeinated drinks regularly, your body will stop reacting with increased blood pressure.

Some people have palpitations (an unpleasant awareness of the heartbeat) after consuming caffeine. If you have palpitations with caffeine in any form, you should avoid all sources of caffeine, including caffeinated water, tea, green tea, coffee, sodas, energy drinks, and chocolate.

Caffeine is a diuretic. It stimulates your kidneys to produce more urine, and dehydration is a risk. But the amounts of caffeine in caffeinated water are unlikely to cause a significant loss of water. People taking as much as 6 milligrams of caffeine per kilogram body weight (that's 360 milligrams if you weight 60 kilograms or 132 pounds) don't have dehydration.

If you are drinking caffeinated water and consuming caffeine in other forms, you should be aware of the signs of dehydration, though:

  • Excessive thirst
  • Dark-colored urine
  • Dry tongue, mouth, and eyes

Caffeinated water should be used with caution by children, adolescents, and people with heart conditions. Caffeine crosses the placenta, and you should be aware that the safe limit during pregnancy is 200 milligrams a day. Besides harmful effects on a baby's brain development, caffeine can also cause miscarriage.

Caffeine disturbs sleep if taken close to bedtime. Caffeine can be present in breast milk and can cause fussiness and poor sleep in breastfed babies


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Alternatives to caffeinated water 


This is the most popular caffeine-containing beverage. A regular mug of coffee has about 100 milligrams of caffeine. Black coffee without sugar has only 2 calories no calories, competing with caffeinated water for providing you caffeine without calories. But sugar, cream, and whole milk add calories and saturated fats to your coffee. Unsweetened coffee with skim milk is a healthy alternative.

Tea or iced tea

A mug of tea has about 75 milligrams of caffeine. The same considerations apply — tea is healthy without too much sugar, cream, or full-fat milk.

Energy drinks

Most energy drinks provide about 80 milligrams of caffeine per can but also have 30 to 40 grams of sugar. That's the amount of added sugar you should have in a whole day.

There was a belief earlier that caffeine-containing beverages should not be counted towards your fluid intake. This was because caffeine was believed to stimulate urine production and cause you to lose water. But we now know that caffeine is a weak diuretic and causes little extra water loss. Caffeinated water, like coffee and tea, counts toward the daily fluid intake.

If you want to have the boost of caffeine without the calories and fats of coffee, tea, or sodas, caffeinated water fits your needs. It also helps you meet your fluid requirements. Most caffeinated water has safe concentrations of caffeine and will provide you with the energy and wakefulness you need without any harmful effects.

Health Solutions From Our Sponsors

Medically Reviewed on 9/26/2022

British Heart Foundation: "Am I drinking too much caffeine?"

Crossroads Family Dental: "Is Caffeinated Water Safe for Your Teeth?"

Frontiers in Psychiatry: "The Safety of Ingested Caffeine: A Comprehensive Review."

Harvard TH Chan School of Public Health: "Caffeine."

National Health Service: "Healthy hydration."