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surfactant · emulsifier

Steareth-21

Commonly feared, low concern·Moderate evidence

A surfactant derived from stearyl alcohol with a higher degree of ethoxylation than Steareth-2, providing enhanced emulsification. It is graded safe for cosmetic use and well tolerated.

The myth vs the evidence

The "eth" suffix indicates ethoxylation, which clean beauty sometimes conflates with PEG concerns. Steareth-21 is approved for cosmetic use. The evidence does not support the fear.

Questions

Is steareth-21 harsh?
Steareth-21 is a mild surfactant and emulsifier used in cleansers and shampoos. Published reviews do not identify it as unusually harsh compared to other surfactants at typical use levels, though concentrations matter.
What does steareth-21 do?
This ingredient helps cleanse by lifting oils and impurities, and also acts as an emulsifier to blend water and oil in formulations. It's milder than some other surfactants.

Products with Steareth-21

References

Cosmetic information for general education, not medical advice. A verdict is a reading of the published evidence, never a guarantee for your skin: any ingredient can irritate someone, so patch test new products and see a professional if you react. Concern is graded on cited evidence, never on hazard-score lists. See how we score.