pH Adjuster

Sodium Hydroxide

Sodium hydroxide (also known as lye or caustic soda) is a highly alkaline inorganic compound used in cosmetics in very small amounts to adjust the pH of formulations. In its pure form it is a potent skin irritant, but it reacts fully with acids during manufacturing — meaning no free sodium hydroxide remains in the finished product. It is particularly important in exfoliant and cleanser formulations where maintaining a precise pH (3–4 for AHAs, 4.5–6 for cleansers) is critical to both safety and efficacy.