Ingredient Guide
Sodium Hydroxide
Also known as: Sodium Hydroxide, Lye, Caustic Soda (cosmetic-grade)
All skin types
What It Is
A strong alkali used in very small amounts as a pH adjuster in skincare formulas. Despite its harsh name, at the trace concentrations used in cosmetics it is safe and functional.
What It Does
Raises the pH of a formula to maintain the correct range for ingredient efficacy and skin safety. Often used alongside citric acid as a complementary pH adjuster.
Best For
pH adjustment — functional ingredient
Benefits
- Essential for pH balancing in acidic formulas
- At cosmetic concentrations, is neutralized during formulation
When to Be Careful
- At the micro-concentrations used in cosmetics, there are no notable concerns
Commonly Found In
SerumsTonersMoisturizersVirtually any pH-adjusted formula
FAQs About Sodium Hydroxide
Is sodium hydroxide in skincare dangerous?
No — at the trace concentrations used in cosmetics, sodium hydroxide is neutralized and functions purely as a pH-balancing agent. The finished product is not caustic. It's a necessary functional ingredient in many formulas.