Hair and hard water: what the studies really show
By Jeremy Fain, founder of Restelys. Updated 17 October 2026. 2 sources cited.
Hard water is often blamed for damaging hair. The studies are more nuanced, which is good news.
Researchers compared hair strands treated for weeks with hard water and with distilled water. The effects on hair strength were modest: hard water alone does not break hair.
However, minerals in hard water can deposit on the hair surface and make it feel rougher and less shiny, especially if it is already dry or damaged.
The answer is simple: a gentle shampoo that rinses easily, then a conditioner that smooths the hair surface. That is the duo we designed, with aloe vera and olive squalane.
Sources
- Srinivasan G., Srinivas C.R., Mathew A.C., Duraiswami D. “Effects of hard water on hair”. International Journal of Trichology, 2013.
- Luqman M.W. et al. “Effect of topical applications of hard and distilled water on hair”. International Journal of Trichology, 2016.
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