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Is Reverse Osmosis Water Good for You? (The Honest Answer)

Updated October 2026·11 min read

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It’s the question almost everyone asks before buying a reverse osmosis system: if RO water removes everything, including minerals, is it actually good for me? The internet is full of strong opinions in both directions. Some call RO water the purest, healthiest option, others warn that “demineralized” water is bad for you. The real answer sits in the middle. Below is what’s established, what’s debated, and where to get advice for your own situation.

The gist

Reverse osmosis is a well-established way to reduce dissolved contaminants in drinking water, including several the EPA regulates, such as lead, arsenic and nitrate. How much a given system reduces is what an NSF/ANSI 58 certification verifies, so check which reductions a system is certified for. The main concern people raise, that RO also removes minerals, is real. For most people, food rather than drinking water is the main source of calcium and magnesium, but how much that matters depends on your diet and your water, so it’s a fair question for your doctor if you have specific health concerns.

If you want the best of both worlds, a remineralizing or alkaline system adds a small amount of minerals back, which many people prefer for taste.

The Case For RO Water (The Benefits)

The strongest argument for RO water is what it removes. Reverse osmosis is one of the more thorough home treatment methods, and it can reduce contaminants that are worth removing (check a system’s certification for the specific reductions it claims):

  • Lead: regulated by the EPA; often comes from older plumbing
  • Arsenic: regulated by the EPA; found in some groundwater and wells
  • Nitrates: regulated by the EPA; a concern in some agricultural areas
  • PFAS (“forever chemicals”): some PFAS are now regulated by the EPA in drinking water
  • Fluoride: for those who choose to avoid it (RO is the main home filter type certified to reduce it)
  • Microplastics and many other dissolved or particulate contaminants

If your tap water contains these at levels that concern you, reducing them is the main reason to consider RO. Check your utility’s annual water quality report (Consumer Confidence Report) or have a private well lab-tested to know what you’re dealing with; see our water testing guide.

The Concern: Demineralization

There is a fair counterpoint. Because the RO membrane removes most of what’s dissolved in the water, it also strips out minerals, mainly calcium and magnesium. This is called demineralization, and it’s the basis for most “is RO water bad for you?” worries.

Two things are true about this:

1. RO water does have less mineral content than tap or spring water. This isn’t disputed. Pure RO water is low in calcium, magnesium, and other dissolved minerals, and tends to be slightly acidic.

2. How much it matters depends on your diet and your water. For most people, food is the main source of calcium and magnesium. How much your tap water contributes depends on how hard it is. Someone eating a varied diet gets most of these minerals from food; someone with a very restricted diet, or who relies on hard water as a mineral source, is in a different position.

What Does the Science Actually Say?

This is where it’s worth being precise rather than alarmist.

The source most “RO water is bad” articles cite is a 2005 World Health Organization publication, Nutrients in drinking-water. It collects papers from a 2003 WHO expert meeting that looked at whether drinking water contributes to mineral intake, prompted mainly by desalinated and other demineralized water. One chapter by an individual contributor argues that long-term drinking of demineralized water may carry health risks; other chapters discuss calcium and magnesium in water and diet more broadly.

Two things are worth knowing when you read claims based on it. First, a contributed chapter in a WHO-published report reflects its author’s review, not a formal WHO guideline or recommendation. Second, the concern is framed around particular contexts: water that is very low in minerals, drunk long-term, by people whose diets are already low in these minerals or who rely on water as a significant mineral source.

The concern is framed around specific contexts: diets low in these minerals, or places where water is a major mineral source. For people with adequate, varied diets, food supplies most of their calcium and magnesium.

In short: both the “RO is perfectly fine” camp and the “you’re losing important minerals” camp are pointing at real facts. They just weight them differently. If you eat a varied diet and like the taste, RO water is widely used for everyday drinking; if you’re concerned, remineralization adds some minerals back, and a doctor or dietitian can advise on your diet.

How Much of Your Minerals Actually Come from Water?

To put the demineralization concern in perspective, here’s where these minerals mainly come from. We don’t quote percentages because the water share depends heavily on your local water hardness and your diet:

Mineral Main dietary sources Amount in tap water Share from water
Calcium Dairy, leafy greens, fortified foods Varies with water hardness Usually smaller than food
Magnesium Nuts, seeds, beans, whole grains, leafy greens Varies with water hardness Usually smaller than food
Potassium Fruits, vegetables, beans Usually low Small

For most people the main source is food: dairy, leafy greens, nuts, beans, and whole grains. Removing the minerals from your drinking water with RO subtracts the water’s share, which is larger if your water is hard and smaller if it’s soft. If you’d still like those minerals (and the taste) back, a remineralizing system adds them in.

What About Acidity and pH?

With the minerals removed, pure RO water tends to be mildly acidic, as are many common beverages. Your body regulates its own internal pH, and the idea that drinking slightly acidic water “acidifies your body” isn’t supported by basic physiology.

If you simply prefer alkaline water, for taste or because it feels better to you, an alkaline/remineralizing system raises the pH back into the neutral-to-alkaline range. That’s a fine preference to have; just know it’s a taste-and-preference choice, not a medical fix.

Who Might Want to Remineralize?

Remineralization (adding a small amount of minerals back after the RO membrane) makes sense if you:

  • Don’t like the flat taste of pure RO water, a common reason people remineralize
  • Eat a mineral-poor or very restricted diet and want every source to count (worth discussing with a doctor or dietitian too)
  • Simply prefer alkaline or mineral water for taste or preference

The good news: remineralization is easy and built into many systems. You don’t have to choose between RO purity and minerals. You can have both.

Systems with remineralization include:

You can also add a standalone inline remineralization cartridge to many existing RO systems; see our remineralization filter guide.

Who Probably Doesn’t Need to Worry About It?

If you eat a normal, varied diet (dairy, leafy greens, nuts, whole grains), food is where most of your calcium and magnesium comes from. For you, remineralizing mostly comes down to taste preference. If you have a specific health condition or dietary restriction, ask your doctor.

Special Cases: Babies, Pets, Aquariums & Plants

A few situations come up often enough to address directly:

  • Infant formula. Two separate questions: germs and fluoride. See the FAQ below, and ask your pediatrician about your baby.
  • Pets. Many owners give animals the same filtered water they drink; ask your vet if you have questions about your pet.
  • Aquariums and reef tanks. RO (and RO/DI) water is the hobby standard, because it gives aquarists a clean baseline to add precisely the minerals their fish or coral need. That’s a real advantage of RO, not a drawback.
  • Plants. Some growers use RO water for sensitive plants because it’s low in dissolved salts. For general outdoor gardening, though,, tap water is fine and RO would be wasteful.

The Bottom Line

Is reverse osmosis water good for you? RO is a well-established way to reduce many contaminants the EPA regulates, and that is its main benefit. It also removes minerals; for most people food is the bigger mineral source, and the concern raised in the WHO-published report applies mainly to people with mineral-poor diets or who rely on water as a mineral source.

If you find pure RO water flat, or you simply prefer mineral/alkaline water, choose a remineralizing system. If you have a specific health concern, talk to your doctor.

Frequently Asked Questions

Is reverse osmosis water bad for your health?

RO water is widely used for everyday drinking. It reduces contaminants such as lead, arsenic, PFAS and nitrates (check a system’s certification for specific claims). It also removes minerals; for most people food is the larger mineral source. If you prefer, remineralization adds minerals back, and your doctor can advise on individual health questions.

Does reverse osmosis water leach minerals from your body?

This claim circulates widely. Your body regulates its mineral balance and internal pH, and RO water mainly differs by containing fewer minerals. The WHO-published report on nutrients in drinking water raised questions mostly about long-term drinking of very low-mineral water by people with low-mineral diets. If you’re concerned, remineralization adds some minerals back, and a doctor can advise.

Should I add minerals back to reverse osmosis water?

It’s optional and mostly about taste. If pure RO water tastes flat to you, or you eat a mineral-poor diet, remineralization is worth it. If you eat normally and like the taste, you don’t need to. Many RO systems include a remineralization stage, or you can add an inline cartridge.

Is reverse osmosis water better than spring water?

They serve different priorities. RO water is lower in dissolved contaminants and minerals. Spring water keeps its natural minerals (and taste) but isn’t put through a membrane. A remineralizing RO system is a middle ground: RO-treated water with some minerals added back.

Is alkaline reverse osmosis water healthier?

Alkaline RO water (RO water with minerals added back to raise the pH) tastes better to many people and restores some mineral content, but there’s no strong evidence that alkaline water itself provides health benefits beyond hydration. Choose it for taste and mineral content if you like. Just don’t expect it to be a health breakthrough. See our alkaline system picks.

Is it safe to drink reverse osmosis water every day?

RO water is widely used for daily drinking. The main consideration is mineral content, which remineralization addresses if you choose; if you have a specific health condition, ask your doctor. For the full picture of what RO water is, see What Is Reverse Osmosis Water?.

Is reverse osmosis water safe for infant formula?

There are two separate issues. Germs and preparation: the CDC says most of the time it’s fine to mix powdered formula with safe tap water, filtered or unfiltered, following the manufacturer’s instructions. For babies younger than 2 months, born prematurely, or with a weakened immune system, the CDC advises extra steps because powdered formula isn’t sterile: boil the water, wait about 5 minutes, then mix, and cool the formula before feeding (CDC: formula preparation). An RO filter doesn’t replace those steps, and a poorly maintained system can harbor bacteria. Ready-to-feed formula doesn’t need water at all. Fluoride: RO water is low in fluoride. The CDC notes that formula mixed with fluoridated water may raise the chance of mild dental fluorosis when formula is a baby’s main food, and that parents can use low-fluoride water some of the time to lessen that (CDC: fluoridation FAQ). Your pediatrician can advise for your baby’s age and health.

Can reverse osmosis water cause a mineral deficiency?

For most people, food is the main source of calcium and magnesium, so the minerals RO removes are the smaller part of intake. People with very restricted diets who relied on water as a mineral source are the case the WHO-published report focused on; if that’s you, talk to your doctor, and consider a remineralizing system.

Is reverse osmosis water bad for your teeth?

Only indirectly: it removes fluoride, which public water systems add to reduce cavities. If you switch to RO water, it’s worth mentioning to your dentist; the CDC also recommends fluoride toothpaste and regular dental checkups. See Does Reverse Osmosis Remove Fluoride? for more.

Keep Reading

Primary sources

Check certifications and water-quality rules yourself: