Purified

Purified / reverse-osmosis water

Written by the VitaWhat editorial team · Medically reviewed by Steve Davis · Last reviewed 19 July 2026 · Editorial policy

Water forced through a fine membrane that removes almost everything.

Where it comes from

Tap or other water pushed under pressure through a reverse-osmosis membrane, removing dissolved solids.

What it contains

  • Very few minerals or contaminants — near-pure H₂O
  • Removes most salts, nitrates, metals and many chemicals

Benefits

  • Very pure; useful where the supply is contaminated
  • Removes unwanted contaminants

Cautions

  • Strips out beneficial minerals too (some systems re-mineralise)
  • Wasteful (rejects water)
  • Flat taste

Sources & references

  1. WHO — Drinking-water
  2. UK Drinking Water Inspectorate

Related entries

Deionised waterDistilled waterAlkaline waterArtesian waterFiltered waterGlacier / iceberg water
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