Purified vs. Distilled vs. Regular Water: What’s the Difference?

There are many different types of available drinking water, including purified water, distilled water, and regular tap water. Each type has its own potential benefits and downsides.

Up to 60% of the human body is made up of water, so drinking a proper amount each day is critical. This vital resource ensures the survival of your body’s cells. It transports nutrients and regulates your internal temperature.

This article covers the differences between these types of drinking water to find out which is best for hydration (and other uses).

Purified water with tubeWhat Is Purified Water?

Purified water is any water that has had its impurities removed. This broad category includes a variety of water subtypes, including distilled water, deionized water, and reverse osmosis water. Bottled water treated by these processes may then meet standards that allow it to be labeled as purified water.

In the United States, bottled water may be labeled purified if it has been treated to meet the standards for purified water set by the U.S. Pharmacopeia. To meet these standards, water must be free of chemicals and contain no more than 10 parts per million to total dissolved solids. If it is treated by distillation or reverse osmosis, it must be free of microbes.

All public drinking water has also been purified in some way before it is considered safe for consumption.

Health Benefits of Purified Water

Public drinking water and commercially available bottled water are treated to remove bacteria and parasites that can cause illness, usually through chlorination and/or filtering.

Filtering water removes impurities, natural minerals, and other inorganic compounds from the liquid. This commonly includes substances like sodium, iron, and chloride.

Drinking purified water reduces the risk of consuming potentially harmful chemicals or substances. With some types of purification that remove minerals, the water has a flatter and blander taste, which some people prefer to the stronger taste associated with water with natural minerals.

Potential Downsides of Purified Water

When purchasing purified water, you can check its mineral content on the label to see whether the process used removes potentially beneficial minerals.

One of the biggest potential downsides of drinking purified water is missing out on the health benefits of some of the substances that might be removed. Many of the minerals that may be removed, depending on the type of purification, play a significant role in your body’s processes.

For example, calcium is influential in building and maintaining strong bones. Magnesium influences the structure of your cell membranes and how your metabolism functions.

Early studies have tied regularly drinking water without these minerals to a higher risk of childhood fractures, certain neurological diseases, and some types of cancer. These associations still need more rigorous examination, however.

Distilled WaterDistilled Water Is a Type of Purified Water

Distilled water is water that is boiled into steam and then recondensed back into a liquid form. Distillation is considered to be another way to purify water. This process also eliminates naturally occurring minerals that are traditionally found in drinking water.

Boiled Water vs. Distilled Water

Boiling purified water at home is not the same as distilling water. Boiling can kill bacteria and parasites, but minerals and other substances can remain in boiled water.9 The distillation process is much more effective in removing impurities, minerals, and other substances.

Health Benefits of Distilled Water

Distilled water is one of the purest forms of bottled water suitable for drinking. Boiling water kills most bacteria, fungi, parasites, and viruses. This significantly reduces your chances of catching a waterborne illness.

Because distilled water is recondensed from steam, most remaining microbes and most chemical impurities are also removed. The purity of this form of water also makes it the preferred choice for laboratory testing and medical procedures due to the low likelihood of contamination.

Potential Downsides of Distilled Water

Though the boiling and recondensing process removes many viruses, minerals, and bacteria, distilled water is not completely free from impurities. Substances that have a boiling point near that of water may vaporize along with water and recondense in the distilled water.

Because of this, an additional water filtration system (like reverse osmosis) may be necessary to get closer to completely pure water.

In addition, drinking distilled water may deprive your body of potentially beneficial nutrients. The distillation process removes minerals like magnesium, calcium, sodium, and potassium, all of which play an influential role in the body.

Does Purified or Filtered Water Work as a Substitute for Distilled Water?

Distilled water is preferable to purified water in some cases.

CPAP Machines and Other Devices

Water containing high amounts of minerals can cause scaly buildup to develop in medical devices like continuous positive airway pressure (CPAP) machines. It may also cause the machine’s components to prematurely break down.

In addition, under-filtered water can also contain higher levels of bacteria, which can lead to infection or airway irritation. As a result, distilled water is recommended for use in CPAP machines, neti pots, and other medical devices that utilize water.

Baby Formula

In most situations, tap water boiled for one minute is safe to use when mixing baby formula. However, there are a few scenarios in which distilled water, filtered water, or bottled water is recommended. These include:

  • Homes with well water
  • Immunocompromised Infants (those with weak immune systems)
  • Developing countries with potentially unsafe water supplies
  • Communities with a recent water contamination event

Child drinking water from tapShould You Choose Purified or Regular Water?

Though manufacturers frequently claim that purified water is healthier than tap water, the jury is still out.

Municipal tap water is tested and usually treated to remove contaminants before it reaches your faucet. Tap water is subject to U.S. Environmental Protection Agency regulations for what levels of impurities and chemicals are acceptable.

Some purification processes remove minerals that may be present in your local tap water and are beneficial to your health. In the end, there is no slam-dunk winner in this debate.

Instead, what is most important is staying hydrated. Adults should aim for at least 9 cups of fluid (water and other beverages) per day, with more depending on sex (women need at least 9 cups, while men need at least 13), environmental conditions, and sweating.

A Note on Gender and Sex Terminology

Verywell Health acknowledges that sex and gender are related concepts but are not the same. To reflect our sources accurately, this article uses terms like “female,” “male,” “woman,” and “man” as its sources do.

inline strainers drinking water from tapHow to Purify Your Drinking Water

Several different methods can purify your home drinking water. These systems are usually either point-of-use devices (like a purifying pitcher or a one-faucet filter) or whole-house systems. Some of the most common purification methods include:

  • Filtration: This process uses fabric or another medium with tiny pores that allow water molecules to pass through but strain out larger contaminants.
  • Reverse osmosis: This is a system that reverses the flow of water and purifies it by sending it through a semipermeable membrane along with several filters.
  • Ultraviolet treatment: This method utilizes specific ultraviolet wavelengths of light to disinfect water and remove harmful contaminants.
  • Water softeners: These systems use resin beads to attract and remove hard particles like magnesium, calcium, and iron from water. Softeners do not filter any viruses or bacteria that may be present.

A Word From Verywell

Water is a vital part of a healthy diet and plays an essential role in multiple body processes. Our lives are busy, and we learn to ignore our thirst, but it’s important to listen to our bodies and ensure we are properly hydrated.

Aviv Joshua, MS

inline strainers holding glass of waterSummary

Purified water uses a filtration system to remove impurities in the liquid. Distillation is one form of purification that boils and recondenses water process to create a purer version of the liquid.

Though these processes may remove certain types of bacteria or minerals, the jury is still out as to whether this is beneficial in the long run. Ultimately, ensuring you stay hydrated seems the most important goal.