Ingredient: Lactic Acid

INCI: Lactic Acid

Sources:  Synthetically Derived for Cosmetic Use

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What is Lactic Acid?

Lactic acid is an alpha hydroxy acid (AHA) naturally present in milk, fruit, vegetables and plants. It is used in personal care products for anti-aging and chemical peels. Depending on the concentration, pH and bioavailability of the lactic acid, it can either act as a gentle exfoliant or a moisturizing agent.

Benefits of Lactic Acid:

In higher concentrations between 5 and 12%, lactic acid exfoliates the skin’s surface by gently breaking down the ‘glue’ between dead epidermal cells and the pilosebaceous unit. The removal of dead skin cells can help to prevent acne breakouts. Lactic acid can also work deeper in the skin; it increases cellular turnover, stimulates fibroblast activity and thickens the dermis to create a more compact and structured epidermis. 

In lower percentages, lactic acid has a moisturizing effect as it reduces transepidermal water loss by repairing the weak lipid skin barrier. It supports the production of the skin’s natural moisturizing factors such as ceramides and glycosaminoglycans (GAGs) that protect the skin against environmental damage. It achieves this without making the skin greasy, safely hydrating even the oiliest of complexions.

Safety & Toxicity:

The Cosmetic Ingredient Review (CIR) Expert Panel concluded that products containing lactic acid are safe for use if its concentration is 10% or less and the final product’s pH level is 3.5 or greater. The formulated products should contain a protective ingredient to shield the skin from increased sun sensitivity and their packaging should also contain advice to consumers to use sunscreen daily.

Editor’s Note:

Lactic acid increases the skin’s sensitivity to the sun. This happens as the outermost layer of the epidermis is removed by its exfoliating properties, leaving the new layer vulnerable to UV rays. Extra care of the skin should be taken by using a broad spectrum UVA/UVB sunscreen. The increased sun sensitivity of the skin is temporary and can be reversed by discontinuing the use of lactic acid.