Buy The Ordinary - Lactic Acid 10% + HA - Beauty (N/A) at THE ICONIC with Free overnight delivery and Free returns! Lactic Acid is an alpha hydroxy acid (AHA) that offers superficial exfoliation to enhance smooth skin texture and radiance. The Lactic Acid 10% + HA formula by The Ordinary is supported by the addition of purified Tasmanian pepperberry extract to offer a comforting benefit to the skin in effort to reduce sensitivity that is associated with acid use. The formula is further supported with the inclusion of hyaluronic acid for multi-depth hydration. A milder 5% formula is available here. This pH of this formula is approximately 3.8 and Lactic Acid has a pKa of 3.8. The pKa value is the most important aspect to consider in formulating with acids as pKa implies acid availability. When pKa is close to pH, there is an ideal balance between salt and acidity, maximizing the efficacy of the acid and reducing the potential of developing irritation. Higher pH values in such a case would increase the concentration of salt, which counter-intuitively would make the formula even more irritating than if the formula was more acidic. Contraindications: Lactic Acid should not be used on sensitive, peeling or compromised skin. Please refer to additional sun protection note and other warnings in provided Directions. This pH of this formula is approximately 3.8. Lactic Acid has a pKa of 3.8 and pKa is the most important aspect to consider in formulating with acids. pKa implies acid availability. When pKa is close to pH, there is an ideal balance between salt and acidity, maximizing effectiveness of the acid and reducing irritation. Higher pH numbers in such a case would increase salt which counter-intuitively would make the formula even more irritating than if the formula was more acidic. Note: While Lactic Acid can result in quick visible benefits, we generally suggest indirect forms of skin exfoliation in favour of direct forms such as this formula due to potential inflammation and sensitivity associated with acids. - A High-Strength Lactic Acid Superficial Peeling Formulation - Apply once per day, ideally in the PM. Can be diluted with other treatments to reduce strength until skin develops tolerance. - Avoid contact with eyes. If irritation persists, discontinue use and consult a physician. - (Sunburn Alert: This product contains an alpha hydroxy acid (AHA) that may increase your skin's sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, and limit sun exposure while using this product and for a week afterwards.) Notes:1. The Tasmanian Pepperberry derivative included in this formula is of plant origin and as such will vary in colour seasonally. This colour variation may be apparent in the formula from time to time. 2. While exfoliating acids can result in quick visible benefits, we generally suggest indirect forms of skin exfoliation for a gentler approach. Please refer to NIOD's Non-Acid Acid Precursor for such a reference. Ingredients: Aqua (Water), Lactic Acid, Glycerin, Pentylene Glycol, Propanediol, Sodium Hydroxide, Sodium Hyaluronate Crosspolymer, Tasmannia Lanceolata Fruit/Leaf Extract, Hydroxyethylcellulose, Isoceteth-20, Trisodium Ethylenediamine Disuccinate, Ethylhexylglycerin, 1,2-Hexanediol, Caprylyl Glycol. Our formulations are updated from time to time as part of our commitment to innovation. As such, the ingredient list shown here may vary from the box of the product depending on time and region of purchase.