Alcohol Denat.

Alcohol Denat. is denatured ethanol — ethanol that has been treated with additives (denaturants) to make it unsuitable for consumption. It is widely used in the cosmetics industry as a multi-functional ingredient.

In skincare products, it acts as a solvent (helping to dissolve and distribute other ingredients), a preservative (offering antimicrobial protection), and a viscosity controller (adjusting product texture). It can also function as an astringent and antifoaming agent. Concentration varies significantly depending on the product type and intended function, ranging from less than 1% to over 90% in some formulations.

Alcohol Denat. works through several mechanisms. As a solvent, it dissolves ingredients that would not mix with water or oil alone, creating a stable, uniform formula. As a preservative, it inhibits the growth of microorganisms by denaturing their proteins.

On skin, alcohol can have an astringent effect — it may temporarily tighten pores and reduce surface moisture. This is why it is sometimes included in formulations targeted at oily or congested skin, though the effect is usually short-lived.

If your skin is sensitive, dry, or prone to irritation, check product concentration and consider patch testing first. Alcohol Denat. is often used in toners, serums, and lightweight formulations; it is less common in heavy creams. Pairing an alcohol-containing product with a good moisturiser can help mitigate drying effects. If you notice tightness, redness, or increased sensitivity, discontinue and allow your barrier to recover.