No credible reason exists to call reverse osmosis water harmful to drink, and the objection usually raised, that it removes beneficial minerals, is real but small: diet supplies calcium and magnesium in quantities drinking water was never going to match. The genuine trade offs with reverse osmosis are taste, wasted drain water and pH, not health.
What the membrane takes out
Reverse osmosis pushes water through a semi permeable membrane that rejects most dissolved solids by size and charge. That is indiscriminate: sodium, nitrate, arsenic and lead go to the drain along with the calcium and magnesium that make water taste rounded. The very property people worry about is the property that makes the technology worth owning when your supply carries something you want gone.
The mineral argument, weighed honestly
Drinking water is a minor mineral source next to food for most people eating an ordinary diet. Removing it changes intake by a small margin, which is why the mineral objection rarely decides anything on its own. Where it does matter is taste and cooking: low mineral water reads as flat, brews weak coffee and can taste faintly sour because dissolved carbon dioxide is no longer buffered. That is a kitchen problem with a kitchen fix.
Remineralization, and when it is worth it
A remineralizing cartridge on the outlet adds back a small amount of calcium and magnesium, lifting pH and restoring body to the taste. Buy it if the flat taste bothers you or if you brew coffee and tea from that tap, not as a health intervention. It is an inexpensive extra stage that fits inline after the tank, and it needs replacing on schedule like every other cartridge in the system.
Decide from your own water report first
Reverse osmosis is a strong answer to a specific question. If your supply carries nothing that a carbon filter cannot handle, you are buying a drain line, a storage tank and a maintenance schedule to solve a problem you do not have. Every community water system publishes an annual Consumer Confidence Report and the EPA maintains a finder for it, so read yours before choosing, or test if you are on a well.
Questions people ask about is drinking ro water bad for you
Does RO water leach minerals out of the body?
No. That claim is not supported by drinking water science, and dietary intake dominates the calcium and magnesium picture for ordinary diets.
Why does RO water taste flat or slightly sour?
The dissolved minerals that give water body are gone, and dissolved carbon dioxide is no longer buffered, which reads on the tongue as flat and faintly acidic.
Do I need a remineralization stage?
Only if you dislike the taste or brew coffee from that tap. It is a palatability upgrade, not a health requirement for a normally fed household.
Is bottled water better than RO from the tap?
Rarely. A maintained under sink system gives you a known process at the point of use, without the storage, handling and repeat purchase of bottles.