Sodium hydroxide

Sodium hydroxide is a strong alkali, but in cosmetics it's added in very small amounts to neutralise acidic ingredients and set the right pH of the finished product. Once the reaction is complete, it no longer acts as a caustic alkali.

This gives the cosmetic a pH suited to skin or hair and allows ingredients such as thickeners and preservatives to work properly. You'll find it in our overnight cream-mask and shampoo bar.