Is distilled water okay to drink in excess? Unpacking the health consequences

November 3, 2025 •

4 min read

According to the World Health Organization (WHO), long-term consumption of demineralized water may be associated with adverse health effects like altered water-salt balance. So, is distilled water okay to drink in excess for your daily hydration needs?

Quick Summary

Excessive or exclusive reliance on distilled water can lead to mineral depletion, electrolyte imbalances, and potential health complications. Regular consumption is not recommended for most people without careful dietary management.

Key Points

Risks of Excessive Consumption: Relying exclusively on distilled water can lead to mineral deficiencies and electrolyte imbalances, potentially causing fatigue, muscle cramps, and headaches.
Distilled Water's 'Aggressive' Nature: Being devoid of minerals, distilled water can leach minerals from the body's tissues and from foods cooked in it.
Electrolyte Imbalance Dangers: Lack of electrolytes like sodium and potassium in distilled water can be particularly risky for athletes or those with dehydration, potentially leading to hyponatremia.
Balanced Diet is Key: For those with a balanced and mineral-rich diet, drinking distilled water in moderation is generally not a health concern, as most minerals come from food.
Alternative Water Options: Mineral-rich water sources, such as tap water (in safe areas), spring water, or remineralized reverse osmosis water, are generally better for long-term daily hydration.
Suitable for Specific Uses: Distilled water is excellent for medical equipment, certain appliances, and lab work where mineral buildup is undesirable.

What is distilled water?

Distilled water is a highly purified form of water created through the process of boiling and re-condensing. The water is heated until it turns into steam, leaving behind virtually all impurities, contaminants, and dissolved minerals. The steam is then collected and cooled, turning it back into a liquid state. The result is exceptionally pure H2O with a very low Total Dissolved Solids (TDS) content, making it ideal for laboratory, medical, and industrial uses where mineral build-up is a concern. However, the very process that makes it so pure for machines and processes is what raises questions about its suitability for long-term human consumption.

The fundamental risks of drinking distilled water excessively

While safe for occasional use or in a balanced diet, the primary danger of drinking distilled water in excess lies in its lack of essential minerals.

Mineral deficiency

Distillation removes key minerals like calcium, magnesium, and potassium that are vital for bodily functions. While water is not the body's primary source of these minerals, it does provide a supplementary amount. When consistently drinking distilled water, especially if your diet is lacking, you run the risk of developing a mineral deficiency.

Calcium: Essential for bone health, muscle function, and nerve signaling. A deficiency can lead to weak bones and increased risk of fractures.
Magnesium: Involved in over 300 enzymatic reactions, magnesium is crucial for muscle and nerve function, blood pressure regulation, and energy production. Symptoms of deficiency can include fatigue, muscle cramps, and headaches.
Potassium: An important electrolyte that helps regulate fluid balance, nerve signals, and muscle contractions. Its depletion can lead to abnormal heart rhythms and muscle weakness.

Electrolyte imbalance

Electrolytes, such as sodium, potassium, and chloride, are lost through sweat and urine. Drinking large amounts of mineral-free distilled water without replacing these electrolytes from other sources can dilute the electrolyte concentration in your body. This can lead to hyponatremia, a dangerously low sodium level in the blood, which can cause symptoms from nausea and confusion to seizures and, in severe cases, be fatal. Athletes, people who are severely dehydrated from illness, and those on certain medications are particularly vulnerable.

The 'aggressive' nature of demineralized water

Because distilled water contains no dissolved solids, it becomes an "aggressive" solvent. This means it actively seeks to absorb minerals from its environment. In your body, this can result in the leaching of minerals from tissues, and some reports suggest it can affect the intestinal mucous membrane over time. For example, when cooking foods in distilled water, significant portions of minerals can be lost from the vegetables and meats into the water.

Who should be cautious about excess distilled water intake?

Several groups should be particularly mindful of their water choice:

Individuals with poor diets: If your diet lacks sufficient fruits, vegetables, and other mineral-rich foods, relying on distilled water could exacerbate nutritional deficiencies.
Endurance athletes: Heavy sweating depletes electrolytes. Consuming only distilled water during or after intense exercise will not replenish these lost minerals, increasing the risk of imbalance.
People with kidney or endocrine disorders: These conditions often involve electrolyte regulation issues, and distilled water can further complicate matters.
Malnourished individuals: For those with already low mineral reserves, drinking distilled water can worsen their deficiency.

Comparison of water types


Feature	Distilled Water	Tap Water	Purified Water (RO)	Spring Water
Mineral Content	Almost none	Varies by location, may contain some beneficial minerals	Very low, as many minerals are removed	Natural mineral content, varies by source
Purity	Exceptionally pure; removes contaminants, bacteria, and minerals	Safe in most developed countries, but may contain trace contaminants	Highly purified; removes most contaminants but can be remineralized	Varies by source, naturally filtered
Taste	Flat and bland due to lack of minerals	Flavor depends on mineral content and treatment	Often flat, similar to distilled but can vary with remineralization	Refreshing, flavor influenced by mineral composition
Health Impact	Risk of mineral deficiency and electrolyte imbalance with excessive intake	Safe for daily hydration in most areas; provides some dietary minerals	Can be a safe, clean option, especially if remineralized	Considered healthy for daily hydration; contains natural minerals

Proper use and alternatives for distilled water

Distilled water is not inherently bad but is best used for specific purposes rather than as a primary hydration source. It is ideal for medical applications, such as for CPAP machines, and for household appliances like steam irons to prevent mineral buildup. For human consumption, particularly for long-term daily intake, other options are generally better.

Tap water: The safest and most economical option in areas with a reliable municipal water supply. Most tap water undergoes purification and retains some minerals.
Filtered water: Uses systems like activated carbon to remove contaminants while keeping beneficial minerals.
Reverse Osmosis (RO) water with remineralization: This system purifies water but then adds essential minerals back in, offering the best of both worlds—clean water with nutritional value.
Mineral water: Sourced from mineral springs, it is naturally rich in minerals and a healthy choice for hydration.
Spring water: Also comes from a natural, underground source and often contains a variety of beneficial minerals.

Conclusion

While distilled water is exceptionally pure and safe for short-term consumption, drinking it in excess or as your sole source of hydration over the long term is not recommended. The complete lack of essential minerals like calcium and magnesium creates a risk of mineral deficiency and electrolyte imbalance. For most people, a balanced diet can compensate for the missing minerals, but groups like athletes and those with pre-existing health conditions face higher risks. For daily drinking, mineral-rich alternatives like tap, spring, or remineralized purified water are healthier and safer choices that support your body's overall nutritional needs. When considering your hydration, pure isn't always the same as healthy. If you have concerns about your water intake, you should consult a healthcare professional.

For more information on the health effects of demineralized water, see the World Health Organization's report on this topic.

Frequently Asked Questions

Yes, distilled water lacks fluoride, which is often added to municipal tap water to promote dental health and prevent tooth decay. Consistent consumption of un-fluoridated distilled water may put you at a higher risk of cavities.

While the distillation process removes pathogens, drinking excessive amounts for an extended period without adequate mineral intake can potentially lead to symptoms of mineral deficiency, which may cause you to feel unwell. It is not toxic in itself.

For healthy adults with a balanced diet, occasional or moderate intake of distilled water is generally safe. Since most essential minerals are primarily obtained from food, the lack of minerals in the water is less of a concern.

Distilled water tastes flat or bland because the distillation process removes all the dissolved minerals and gases, such as calcium, magnesium, and dissolved oxygen, that contribute to the flavor and crispness of normal drinking water.

While often used for formula, un-sterilized distilled water is not recommended for infants under 4 to 6 months old. For older babies, using it is safe, but it lacks the minerals vital for development. You should always consult a pediatrician.

Distilled water is a type of purified water created by boiling and re-condensing, which removes minerals. Other purification methods like reverse osmosis also remove contaminants but can be remineralized to restore beneficial minerals.

Some studies suggest an association between low mineral water (including distilled water) and cardiovascular issues, but there is no conclusive evidence that distilled water lowers blood pressure. Any changes in fluid balance from excessive intake could, however, affect blood pressure.