Why is potassium hydroxide in my skincare product?

Potassium hydroxide is used in skincare products primarily as a pH adjuster. It helps to bring the product's pH level into a range that is safe and effective for topical application, preventing it from being too acidic or too alkaline.

Is potassium hydroxide safe?

When used in cosmetic formulations, potassium hydroxide is present in very low concentrations and is carefully neutralized, making it safe for use. In its concentrated form, it is a strong base and can be corrosive, but this is not how it is used in finished products.

Home › Ingredients › Potassium Hydroxide

Potassium Hydroxide

Also known as: Caustic Potash, Potash Lye

Potassium hydroxide is a strong alkaline compound used in cosmetics to adjust the pH of a product. It helps to ensure that the product's acidity or alkalinity is within a safe and effective range for skin application. It is also used in the saponification process to make liquid soaps.

PH adjusterVegan

BenefitNone 0 / 4

RiskModerate 1.5 / 4

Irritation i1.5 / 4

Risk of short-term irritation — stinging, burning, dryness, redness, or discomfort. Common for strong actives, acids, retinoids, fragrances, and harsh surfactants.

Sensitization i0.5 / 4

Risk of allergic contact dermatitis or immune-based reactions. Fragrance allergens, preservatives, botanicals, and some dyes may score here.

Rated by SpottyLabs' ingredient methodology, independent of brands.

Things to watch

can be highly corrosive in concentrated forms
potential for irritation if not properly neutralized

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Products with Potassium Hydroxide

La Roche-Posay

Pure Vitamin C Eye Cream

4.8/ 518/8/4

Altruist

Dermatologist Sunscreen SPF50

4.3/ 510/8/5

Moroccanoil

Frizz Control Conditioner

4.3/ 517/23/9

L'Oréal Paris

Revitalift Vitamin C Brightening Daily Moisturizing Cream

4/ 516/17/7

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Frequently asked questions

Why is potassium hydroxide in my skincare product?: Potassium hydroxide is used in skincare products primarily as a pH adjuster. It helps to bring the product's pH level into a range that is safe and effective for topical application, preventing it from being too acidic or too alkaline.
Is potassium hydroxide safe?: When used in cosmetic formulations, potassium hydroxide is present in very low concentrations and is carefully neutralized, making it safe for use. In its concentrated form, it is a strong base and can be corrosive, but this is not how it is used in finished products.