Potassium Stearate



No known benefits

Potassium Stearate at a glance

  • Potassium salt of stearic acid
  • Primarily used as an emulsifier to keep water and oil-based ingredients from separating
  • Also used as a cleanser
  • Ruled safe as used in cosmetics

Potassium Stearate description

Potassium stearate is the potassium salt of the fatty acid stearic acid. According to one of its manufacturers, it is primarily used as an emulsifier in cosmetics, meaning it keeps water and oil-based ingredients from separating. It also serves the same function in food products. It also works as a cleansing ingredient and is often found in traditional bar soaps for both its cleansing and emulsifying abilities. A fine, white powder in pure form, potassium stearate has been ruled safe as used in cosmetics (where it is used in amounts up to 7.5% in leave-on products) by the independent Cosmetic Ingredient Review panel.

Potassium Stearate references

  • https://www.americanelements.com/potassium-stearate-593-29-3
  • https://www.cosmeticsinfo.org/ingredients/potassium-stearate/
  • https://www.ulprospector.com/en/na/PersonalCare/Detail/1626/59525/Potassium-Stearate-OPK-1000
  • https://www.cir-safety.org/sites/default/files/Fatty%20Acids.pdf

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings


Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.


Necessary to improve a formula's texture, stability, or penetration.


Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.


There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.


May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.


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Not rated

We have not yet rated this ingredient because we have not had a chance to review the research on it.