Can you drink water with a high pH level? A Scientific Breakdown

September 28, 2025 •

4 min read

The U.S. Environmental Protection Agency (EPA) recommends drinking water fall within a pH range of 6.5 to 8.5. Given this, can you drink water with a high pH level? The answer involves understanding your body's natural regulation and the actual science behind alkaline water claims.

Quick Summary

While generally safe for most people, particularly within EPA guidelines, excessively high pH water can have aesthetic issues and potential health risks, especially for individuals with kidney conditions. The body's internal pH is tightly regulated, and most exaggerated health claims lack strong scientific support.

Key Points

Moderate pH is Safe: Drinking water with a pH up to 8.5 is generally considered safe for most people, according to EPA recommendations.
Body Regulates Itself: Your body's internal pH is tightly regulated by your kidneys and lungs and is not significantly altered by drinking moderately alkaline water.
Unproven Claims: Many advertised health benefits of alkaline water, such as preventing cancer or altering body pH, are not supported by strong scientific evidence.
Risks at Extreme Levels: Very high pH water (above 9.8) can be risky, especially for individuals with kidney disease, and can interfere with digestion and medication absorption.
Aesthetic Problems: High pH water often has a bitter taste and can cause mineral scaling that damages pipes and appliances over time.
Testing and Treatment: If you have concerns, you can test your water's pH at home and use simple methods like adding lemon juice or installing a filtration system to adjust it.

Understanding the pH Scale and Your Body

Water's pH level indicates its acidity or alkalinity on a scale of 0 to 14. A pH of 7 is neutral, below 7 is acidic, and above 7 is alkaline (or basic). The human body is remarkably efficient at maintaining a stable internal pH, with blood pH tightly regulated around 7.4. This process is managed by organs like the kidneys and lungs, which filter out excess acids and bases to maintain homeostasis. Because of this, drinking moderate amounts of alkaline water will not significantly alter your blood's pH level. However, the effects on digestive systems and other health factors are worth considering.

How Different pH Levels Affect Drinking Water

Naturally occurring high pH water often gets its alkalinity from minerals like calcium, magnesium, and potassium, which it picks up from surrounding bedrock. This is common in well water and some natural springs. Conversely, artificially produced alkaline water, often created through a process called electrolysis, can have much higher pH levels, sometimes exceeding 10. While the EPA recommends a range of 6.5 to 8.5, slightly higher pH water is usually not a health concern but can cause practical issues.

Potential Health Effects and Considerations

While many companies selling alkaline water claim a wide range of health benefits, from detoxifying the body to preventing cancer, the scientific evidence to support these assertions is largely weak or nonexistent. It's crucial to rely on established medical science rather than marketing hype. There are, however, some limited areas of research and some proven risks to be aware of.

Limited Potential Benefits (Requires More Research)

Acid Reflux Relief: Some studies suggest that alkaline water with a pH of 8.8 may help temporarily deactivate pepsin, an enzyme responsible for acid reflux symptoms. However, this effect is temporary, and more effective treatments exist.
Improved Hydration: A few small studies have indicated that alkaline water might improve hydration status after intense exercise.
Bone Health: Some research points to a potential link between alkaline water consumption and improved bone density markers in postmenopausal women, though more investigation is needed.

Documented Risks and Cautions

Altered Stomach Acidity: Consuming large quantities of highly alkaline water can temporarily neutralize your stomach's natural acidity, which is essential for proper digestion and killing harmful bacteria.
Kidney Disease Complications: Individuals with impaired kidney function should be particularly cautious. The kidneys are crucial for balancing blood pH, and excessive alkaline intake can stress this process, potentially leading to hyperkalemia (high blood potassium), especially with very high pH water (>9.8).
Interference with Medication: High pH water can interfere with the absorption of certain medications by changing the stomach's pH level.
Mineral Imbalance: In some cases, overconsumption could lead to mineral imbalances, like excessively high calcium, which can cause other health issues.

Aesthetic and Practical Considerations

Beyond the health aspects, high pH water can have noticeable effects on your home and daily life. Water with a pH above 8.5 often has a bitter taste that many find unpleasant, and it can affect the flavor of beverages like coffee. A more significant issue is the mineral buildup, or scaling, that high pH water can cause. This can clog pipes, reduce the efficiency of appliances like water heaters, and leave unsightly deposits on fixtures.

How to Manage High pH Water

Test your water: You can purchase an at-home testing kit to check the pH of your tap or well water. This will give you an accurate starting point.
Install a filtration system: For a permanent solution to persistent high pH issues, consider a water filtration system, such as a neutralizing filter, installed at your water source.
Use acid injection: In more severe cases, a professional may need to install an acid-injection system to neutralize the water as it enters your home.
Add natural acid: For temporary adjustment of small quantities, adding a few drops of lemon juice or a splash of vinegar can lower the pH.

The Bottom Line on High pH Water

For the average healthy person, drinking moderately alkaline water (pH 8-9) is not considered harmful, as the body can effectively regulate its own pH balance. The supposed health benefits often associated with it are largely unproven by robust scientific studies. However, excessively high pH water (above 9.8) should be approached with caution due to potential health risks, especially for those with kidney disease. The best approach is to ensure your drinking water is within the EPA's recommended range and, if concerned, consult a healthcare professional. For more information on the potential pitfalls, consider reading expert health resources Is alkaline water better? - Harvard Health.


Feature	Regular Tap Water (pH ~7)	Bottled Alkaline Water (pH ~8-9)	Very High pH Water (pH >9.8)
Taste	Neutral, standard	Often slightly sweeter or smoother	Bitter, soapy taste
Cost	Low (municipal supply)	High (premium product)	Can be very expensive for ionized systems
Health Impact (General)	Generally safe	Generally safe, unproven benefits	Potential risks with excessive consumption
Effect on Blood pH	No significant effect	No significant effect	No significant effect
Digestive Impact	Neutral	Temporary reduction in stomach acid possible	Significant interference with stomach acid possible
Risk for Kidney Patients	Low risk	Low risk	High risk; avoid unless supervised
Aesthetic Issues	Minimal (varies)	Minimal	Scaling on pipes and fixtures

Frequently Asked Questions

The U.S. Environmental Protection Agency (EPA) recommends that public water systems maintain a pH level between 6.5 and 8.5 for drinking water. This range is considered safe and optimal for human consumption.

No, this is a dangerous and scientifically unsupported claim. Robust scientific research has not found evidence that alkaline water can prevent or treat cancer, or detoxify the body in the ways some manufacturers suggest. Your body has its own systems for regulating pH and filtering toxins.

No. The pH of your blood is tightly controlled by your kidneys and lungs to remain in a very narrow, slightly alkaline range around 7.4. Drinking alkaline water does not significantly alter this balance. Only severe medical conditions can cause a sustained change in blood pH.

Regularly drinking water with a very high pH level (above 9.8) can pose several risks. It may cause a mineral imbalance, disrupt stomach acidity needed for digestion and immunity, and is particularly dangerous for people with kidney disease. Excessive consumption can potentially lead to symptoms like nausea or confusion.

Yes. Water with a high pH is often 'hard' water, which can lead to mineral scaling or encrustation on pipes and water-using appliances. This can reduce water flow, decrease appliance efficiency, and cause damage over time.

You can test your water's pH using a simple, inexpensive kit available at most home improvement or online stores. For a more comprehensive analysis, you can send a water sample to a testing laboratory.

For individual glasses, you can lower a high pH by adding a few drops of lemon juice or vinegar. For a more permanent solution, you can install a water filtration or neutralizing system. For severe cases, a professional installation might be necessary.