Is it better to drink water with higher or lower pH?

November 27, 2025 •

4 min read

According to the World Health Organization (WHO), the ideal pH level for drinking water is between 6.5 and 8.5. While marketing claims often promote higher-pH water for superior health, the truth is that a neutral pH is generally safe and sufficient for most people, and extremes carry potential risks.

Quick Summary

The human body tightly regulates its internal pH balance, making the pH of drinking water largely irrelevant for most individuals. Acidic water can be corrosive and leach heavy metals from pipes, while highly alkaline water may cause unpleasant taste and scale buildup. Neither is superior for general hydration.

Key Points

Neutral is Optimal: The World Health Organization (WHO) recommends drinking water with a pH between 6.5 and 8.5, which is ideal for most people.
Alkaline Claims are Mostly Hype: Claims that high-pH water can neutralize body acid, slow aging, or cure diseases are largely unsubstantiated by science.
Your Body Regulates pH: The lungs and kidneys naturally maintain a very stable blood pH, rendering the pH of drinking water largely irrelevant for your body's overall balance.
Acidic Water Risks: Water with a low pH (<6.5) is corrosive and can leach harmful heavy metals like lead and copper from pipes into your water supply.
Highly Alkaline Water Issues: Excessively alkaline water can taste bitter, cause scale buildup in plumbing, and may pose risks for individuals with certain health conditions, like kidney disease.
Cost vs. Benefit: Alkaline bottled water is significantly more expensive with no proven health advantage for general hydration, making regular, safe tap water a more economical and reliable choice.

Understanding the pH Scale

To understand whether higher or lower pH is better for drinking water, it's essential to know what pH actually is. The pH scale measures the concentration of hydrogen ions in a solution, indicating its acidity or alkalinity. The scale runs from 0 to 14, with 7 considered neutral. A substance with a pH below 7 is acidic, and one with a pH above 7 is alkaline (or basic). Each whole number change on the scale represents a tenfold shift in acidity or alkalinity.

Pure, distilled water has a neutral pH of 7, but most natural water sources have a slightly wider, safe range, typically between 6.5 and 8.5. The final pH of your tap water can be influenced by local mineral content, human activity, and treatment processes.

The Truth About Alkaline Water Claims

In recent years, alkaline water, often marketed with a pH between 8 and 9, has gained popularity based on health claims that it can neutralize acid in the body, slow aging, prevent chronic diseases, and offer better hydration. However, the vast majority of these claims lack strong scientific support. The human body has sophisticated and tightly regulated systems, primarily involving the lungs and kidneys, to maintain a very specific blood pH range of 7.35 to 7.45. Introducing slightly alkaline water has a negligible and temporary effect, as the stomach's powerful gastric acids will neutralize it almost immediately.

Some studies have shown potential, but limited, benefits for specific conditions, such as:

Acid Reflux: Inactivating pepsin, the stomach enzyme responsible for reflux, may help manage laryngopharyngeal reflux disease.
Chronic Kidney Disease: Some research suggests marginal improvements in certain markers for postmenopausal women with metabolic syndrome.

It is crucial to note that many studies highlighting alkaline water's benefits are small, funded by the industry, or involve animal subjects, which limits their applicability to the broader human population.

The Risks of High and Low pH Water

While neutral or slightly alkaline water (within the recommended 6.5-8.5 range) is generally safe, extremes in either direction can present issues, both for health and household plumbing.

Risks of Acidic (Lower pH) Water

Corrodes Plumbing: Acidic water, with a pH below 6.5, is corrosive to metal pipes and fixtures. This can cause leaks and release heavy metals into the water supply.
Heavy Metal Contamination: The corrosion process can leach heavy metals, such as lead, copper, and arsenic, into your drinking water, leading to toxicity risks over time.
Metallic Taste and Staining: Low pH water often has a metallic or sour taste and can cause blue-green or reddish stains on fixtures and laundry.
Erodes Tooth Enamel: Regularly consuming acidic water may contribute to the erosion of tooth enamel, increasing the risk of dental cavities.

Risks of Highly Alkaline (Higher pH) Water

Unpleasant Taste and Feel: Water with a pH above 8.5 can have a bitter taste and a slippery feel.
Mineral Buildup: Highly alkaline water can lead to scale buildup in pipes, faucets, and water-using appliances, reducing their efficiency.
Potential Health Complications: For individuals with specific health issues, particularly kidney disease, excessively alkaline water could disrupt the body's mineral balance and potentially lead to adverse effects.

Comparison of Different Water pH Types


Feature	Acidic Water (pH < 6.5)	Neutral Water (pH ~ 7)	Alkaline Water (pH > 7.5)
Taste	Metallic or sour	Balanced, clean taste	Often has a smoother or bitter taste
Corrosion	Highly corrosive to metal pipes	Non-corrosive for pipes	Less corrosive; can cause scale buildup
Mineral Content	Can be elevated due to leaching from pipes	Varies depending on the source; often contains trace minerals	Contains higher concentrations of alkaline minerals like calcium and magnesium
Health Impact	Can leach heavy metals into the water, potentially causing health risks	Safe and sufficient for general hydration	Potential limited benefits for specific conditions like acid reflux, but widely promoted claims are unsubstantiated
Cost	Typically inexpensive, but potential damage to plumbing is costly	Most cost-effective, readily available in tap water	Significantly more expensive due to specialized processing and marketing

Final Recommendations and Conclusion

When considering whether it's better to drink water with a higher or lower pH, the scientific consensus supports neither extreme for overall health. The human body is remarkably adept at regulating its internal pH, and there is no conclusive evidence that manipulating the pH of your drinking water provides significant health benefits for the average person. Drinking water with a pH within the widely recommended range of 6.5 to 8.5, as endorsed by organizations like the WHO and EPA, is both safe and sufficient for maintaining hydration.

For those concerned about their home water supply, particularly if the taste is off or there are signs of pipe corrosion (e.g., blue-green stains), testing the water is a sensible step. If the water is found to be too acidic, treatment systems can correct the issue. Consumers should be wary of expensive, highly marketed alkaline waters that promise miracle health benefits, as these claims are often unsubstantiated. Ultimately, prioritizing consistent hydration with clean, safe water is the most important factor for good health, regardless of a slightly higher or lower pH.

For more information on the official guidelines for drinking water quality, consult the World Health Organization's website. World Health Organization - Guidelines for Drinking-water Quality

Frequently Asked Questions

No, drinking alkaline water does not significantly change your body's overall pH. Your body has sophisticated systems, like the kidneys and lungs, to maintain a very narrow and stable blood pH range. The alkaline effect of the water is neutralized by your stomach acid.

If your tap water has a low pH (below 6.5), it is more likely to be corrosive. This can cause metal from your pipes to leach into the water, potentially contaminating it with heavy metals such as lead and copper. It may also result in a metallic taste and blue-green stains on fixtures.

Artificially produced alkaline water is made using a process called electrolysis, which may or may not add minerals back in. Naturally alkaline water acquires its alkalinity from minerals it picks up as it passes over rocks in nature. The health benefits, if any, come from the minerals, not just the pH.

Yes, excessively alkaline water (above pH 8.5) can have a bitter taste and lead to scale buildup in appliances and pipes. For some people with specific health conditions, such as kidney disease, consuming highly alkaline water may pose risks and should be discussed with a doctor.

You can use a simple, inexpensive home test kit to check your water's pH. If you notice a metallic taste, unusual stains on your plumbing (blue-green or reddish), or residue buildup, these could also be signs of imbalanced water pH.

Absolutely not. Water with a neutral pH is perfectly healthy and is the standard for pure water. It is safe for consumption and effectively hydrates the body without introducing unnecessary mineral concentrations or potential risks associated with pH extremes.

While some proponents claim alkaline water provides better hydration, most experts state that the amount of water you drink is the most important factor for hydration, not the pH level. The body regulates hydration effectively with regular water.