Is Coffee a Diuretic?

is coffee a diuretic

Is coffee really a diuretic?

COFFEE is a drug. The drug is “any substance that causes changes in the organism’s body and mind when consumed”. Some people don’t even know that they are innocently ingesting drug when they sip brewed coffee or whatever coffee drink. We had always known coffee plainly as a healthy and desirable beverage.

But the truth is: caffeine- like nicotine and alcohol- is categorized as a recreational drug because it is mainly used for pleasure rather than for medicinal purposes”; this is why coffee is more popular as a trigger for the happiness-giving dopamine than as a source of caffeine. 

image source by cv pharmacy

Does coffee make you retain water?.

Have you ever experienced wanting to urinate again after relieving yourself awhile following a coffee-drinking spree? The accumulated caffeine you got from coffee is the likely culprit. Caffeine “is a substance that tends to increase the flow of urine, which causes the body to get rid of excess water”. You may regularly enjoy a few cups of your favorite coffee but you may not need to urinate at all. It stands to reason that you gain some kind of tolerance to caffeine if you are a regular coffee-drinker. 

Do I need to drink more water if I drink coffee?

Your recommended water intake includes all sources – drinking water, sports drinks, and fruits and coffee does provide water. But, they also contain caffeine, which can make you lose more water when you pee. Most healthy people can safely drink about 2 to 4 8-ounce cups of coffee each day.

Can you count coffee as water intake?

You can count coffee in your daily water intake. Many used to believe that they were dehydrating, but that myth has been debunked. The diuretic effect does not offset hydration.

Is coffee a diuretic or antidiuretic

Caffeine is a relatively weak diuretic because the body has an “anti-diuretic hormone that works with the hormone aldosterone, which stimulates active sodium re-absorption (and water as a result). It takes as much as 360 milligrams for caffeine to deliver the diuretic effect.

The usual 8-ounce cup of coffee-depending on whether the brew is regular or strong’- would contain 95 to 200 milligrams of caffeine”. This means that you’ll have to successively imbibe 2 cups of strong coffee to experience coffee’s diuretic effect. It’s not difficult to prevent loss of water to urine by drinking sufficient plain water and to prevent potential dehydration.

Caffeine increases the flow of urine “primarily because it increases blood pressure within the kidney’s glomerular capillaries- which increases filtration, resulting in more urine flow”. To understand how urine flows, you may view how the kidney functions in YouTube:

Here you can visualize how and confirm that the kidney’s 3 fundamental functions- filtration, reabsorption, and secretion- govern the urination process.

“In the filtration process, the functional units of the kidney collect toxic cells, proteins, and molecules from the blood and convert these to urine. Re-absorption is the process where solutes and water are put back in the bloodstream. Secretion is the process where toxic substances and drugs are secreted to the tubular lumen.

READ Related Article:  Cool Coffee Facts

This formula explains how much urine is produced:

Urinary Excretion/Urination Rate = Filtration Rate – Re-absorption Rate + Secretion Rate”.

You can see that the by-products of metabolism and bodily wastes minus substances returned for reuse plus the toxic substances secreted into the tubular lumen produce the approximately 800-2,000 milliliters (ML) of urine you eliminate every day.

Therefore, if caffeine is known to reduce filtration- that increases urine flow and potentially causes dehydration- why drink coffee?

Caffeine is a mild diuretic.

There is more worry than danger in possibly drinking more coffee than you might need to take; there is a remote possibility that you get dehydrated for drinking excessive coffee. The worry would be negligible compared to the good mood or euphoria that the “neurotransmitter dopamine” in your brewed, or instant, or special, or ordinary, or plain, or grass-fed, or yogurt-enriched, or milky, or chocolaty or any coffee is certain to deliver to you each morning every day.

Top natural diuretics

Here are the top 8 natural diuretics

  1. Coffee
  2. Dandelion Extract.
  3. Horsetail.
  4. Parsley.
  5. Hibiscus.
  6. Caraway.
  7. Green and Black Tea.
  8. Nigella Sativa.


If you’re worried you might get dehydrated for drinking coffee, take only as much as your body can tolerate or switch to decaffeinated coffee. Read our article on coffee health benefits.


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Self-proclaimed coffee drinker. I would, on a typical day, start my day by grinding my coffee with a manual grinder and use a French Press as a starter (2 cups), then a pour-over in the afternoon (4 cups). I had my fair share as a barista but I prefer to drink it, not serve it.