Skin pH, and why your soap matters
By Jeremy Fain, founder of Restelys. Updated 17 October 2026. 2 sources cited.
The surface of the skin is slightly acidic. An overly alkaline soap upsets this balance; a gentle one respects it.
The pH of the skin surface averages around 5, slightly acidic. This acidity helps the enzymes that make the barrier’s lipids and supports a balanced skin flora.
Traditional soaps are alkaline, with a pH close to 9 or 10. Used often, they temporarily raise the skin’s pH, which can make it drier and more reactive.
Our cleansers are formulated with a pH close to that of the skin; the exact value of each product will be shown on its page at launch.
Sources
- Lambers H. et al. “Natural skin surface pH is on average below 5, which is beneficial for its resident flora”. International Journal of Cosmetic Science, 2006.
- Ali S.M., Yosipovitch G. “Skin pH: from basic science to basic skin care”. Acta Dermato-Venereologica, 2013.
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