Lactic Acid 10% + HA is an alpha hydroxy acid solution that provides effective exfoliation aimed at the skin surface. It is supported with purified Tasmanian pepper extract that has been proven to reduce irritation and sensitivity that may be ociated with the use of acids. This water-based serum is ideal for dry skin. This pH of this formula is approximately 3.8. Lactic acid has a pKa value of 3.8 and the pKa value is the most important aspect to consider when formulating with acids. pKa implies the availability of acid. When the pKa value is close to the pH, there is an ideal balance between salt and acid, maximising the effectiveness of the acid and reducing irritation.