Why is distilled water unsuitable for drinking?

December 8, 2025 •

4 min read

A report from the World Health Organization (WHO) has highlighted potential adverse health effects of consuming demineralized water over the long term, including electrolyte imbalances and decreased metabolic function. This has brought to light crucial questions about using distilled water as a primary drinking source, despite its perceived purity.

Quick Summary

Distilled water, produced by boiling and condensing steam, lacks all minerals. Long-term consumption is not recommended due to potential mineral deficiencies, electrolyte imbalances, and poor hydration compared to mineral-rich water.

Key Points

Mineral Deficiency: Distilled water is stripped of essential minerals like calcium, magnesium, and potassium, which are important for good health.
Electrolyte Imbalance: The absence of electrolytes can lead to imbalances, which may cause fatigue, headaches, and muscle cramps.
Less Hydrating: Because it lacks electrolytes, distilled water is less effective at replenishing lost fluids and minerals after sweating.
Aggressive Solvent: Being mineral-free, distilled water can leach minerals from your body's tissues, including bones and teeth, over time.
Poor Flavor: The absence of minerals gives distilled water a flat, bland taste that some find unappealing, which could lead to reduced water intake.
Inappropriate for Long-Term Use: While safe in small, short-term doses, it is not recommended as a regular source of hydration, especially for vulnerable individuals.

Understanding the Distillation Process

Distilled water is created by a process of boiling and condensation. Water is heated to its boiling point, turning it into steam. This steam rises, leaving behind impurities, heavy metals, and dissolved minerals in the boiling chamber. The pure steam is then collected and cooled, condensing back into a liquid state. This process results in a highly pure form of water, essentially H2O, but also one that is completely stripped of its natural mineral content, such as calcium, magnesium, and potassium.

The Problem with a Lack of Minerals

While distillation effectively removes harmful contaminants like bacteria and chemicals, its primary drawback for drinking is the complete absence of beneficial minerals. A normal diet provides most essential minerals, but drinking water serves as a key source for supplementing these nutrients. Long-term, consistent consumption of demineralized distilled water can lead to several health issues related to mineral deficiency.

Potential consequences of mineral deficiency include:

Fatigue and weakness: Magnesium deficiency can contribute to feelings of tiredness and weakness.
Muscle cramps: A lack of magnesium and calcium can lead to muscle cramping and stiff joints.
Headaches: Insufficient levels of magnesium and calcium can trigger headaches.
Impaired bone health: Long-term deprivation of minerals like calcium can weaken bones over time, potentially leading to conditions like osteoporosis.

The Aggressive Nature of Demineralized Water

Distilled water is often described as 'hungry' or 'aggressive' because its pure, mineral-free state makes it an effective solvent, eager to absorb whatever it touches. When consumed, this means it can draw small amounts of minerals and electrolytes from the body, including from teeth and bones, to create a balance. Over time, this constant leaching of minerals can be detrimental to your health. This aggressive property also means that if stored in certain containers, such as metal or some plastics, it can potentially leach harmful chemicals from the container itself.

Electrolyte Imbalance and Hydration

Electrolytes, such as sodium and potassium, are vital for regulating water distribution and nerve function throughout the body. When we sweat, we lose both water and electrolytes, and normal drinking water helps replenish these. Since distilled water lacks these electrolytes, it's not as effective at rehydrating the body and replacing what is lost. Consistent consumption without a balanced diet that provides sufficient minerals can lead to an electrolyte imbalance. The World Health Organization has noted that drinking water with low mineral content can also lead to increased urine output, further exacerbating the loss of vital minerals.

Palatability Issues

Most people find the taste of distilled water to be flat or bland. The minerals found in natural or filtered tap water contribute to its flavor profile. For some, the unappealing taste of distilled water might lead them to drink less overall, which can result in inadequate hydration. This can be a significant hurdle for maintaining healthy drinking habits, especially for those who rely on it as their sole water source.

Comparing Distilled Water to Other Options


Feature	Distilled Water	Spring Water	Purified (RO) Water
Mineral Content	Essentially none; all minerals are removed.	Rich in naturally occurring minerals from the earth.	Removes many contaminants but may retain some minerals, or have them added back.
Purification Method	Boiling water into steam and then condensing it back into liquid.	Naturally filtered through rock formations underground.	Forced through a semi-permeable membrane under pressure.
Taste	Flat and bland due to the absence of minerals.	Crisp and refreshing, with taste influenced by mineral content.	Clean and fresh, with a taste often improved over tap water.
Best Uses	Appliances (irons, CPAP machines), laboratories, medical applications.	Everyday drinking, cooking, hydration.	Everyday drinking, cooking, general household use.
Health Considerations	Not ideal for long-term drinking due to mineral deficiencies.	Supports hydration with essential minerals.	A safe and reliable drinking option, especially with remineralization.

For Specific Groups and Considerations

For most healthy adults with a balanced diet, drinking distilled water in the short term is not likely to cause severe harm. However, certain individuals should be particularly cautious. Performance athletes, for example, lose a significant amount of electrolytes through sweat and require replenishment that distilled water cannot provide. People who are malnourished, or those with certain medical conditions like chronic kidney disease or malabsorption syndromes, are also at a higher risk of electrolyte imbalances and mineral deficiencies. Additionally, medical professionals recommend consulting a pediatrician before giving infants distilled water as their sole water source, especially when mixing with formula. For information on mineral content in different water types, consult research published by institutions like the World Health Organization.

Conclusion: Not for Consistent Hydration

While distilled water serves crucial purposes in medical, industrial, and specific household applications where absolute purity is required, it is fundamentally unsuitable for consistent human consumption. The distillation process strips water of its vital, naturally occurring minerals and electrolytes, which are necessary for proper hydration and numerous biological functions. The potential for mineral deficiencies, electrolyte imbalance, and its unpalatable taste make mineral-rich alternatives like spring or properly filtered water far superior choices for daily drinking. Prioritizing mineral-retaining filtration methods or mineral-rich natural sources is the wisest course of action for long-term health and hydration.

Frequently Asked Questions

Yes, for most healthy individuals, drinking distilled water occasionally or for a short period is generally safe, especially if you have a balanced diet rich in minerals.

Distilled water has all minerals and impurities removed via boiling and condensation. Spring water is naturally filtered and retains minerals. Purified water is treated to remove contaminants but may still contain some minerals, unlike distilled water.

While often claimed, there is little scientific evidence to support this. The idea is based on its 'pure' state pulling toxins, but this action also pulls out necessary minerals, making it potentially harmful in the long run.

You can cook with distilled water, but some studies suggest that using it may leach minerals from the foods you are cooking, potentially reducing their nutritional value.

For healthy kidneys, short-term use is fine. However, relying solely on it for the long term could impact the delicate balance of minerals that the kidneys regulate and may increase urine output, contributing to electrolyte imbalance.

Distilled water tastes flat because the distillation process removes all dissolved minerals and salts. These minerals are what give natural and filtered tap water its characteristic flavor.

Mineral-rich water sources like spring water or tap water that has been filtered (e.g., using activated carbon or reverse osmosis systems with remineralization) are better for daily consumption.

While using distilled water for mixing formula is common, it's not ideal as a baby's sole water source. Always consult a pediatrician, as babies need specific minerals for growth that distilled water lacks.