Ingredient dictionary

Sodium Stearate

Also listed as: Sodium Octadecanoate

Sodium stearate is the sodium salt of stearic acid, a fatty acid, and it works as a soap. Its main jobs are cleansing and giving products body and structure. It is on the label of 18 products in our library. Checked against our library November 6, 2026.

What Sodium Stearate does

Cleans by lifting oil and dirt
Thickens and firms up creamy textures
Helps stabilize oil and water blends
Adds a soft, creamy lather

Sodium stearate is made by reacting stearic acid, a fatty acid taken from plant or animal fats, with sodium hydroxide, a strong alkali that is fully used up in the reaction. This reaction turns the fat into a soap, the same basic process used in traditional soap-making.

Formulators use it because it cleans well and holds its shape. In bar cleansers it does the washing. In deodorant sticks and shaving soaps it gives structure and a dense, creamy lather. In lotions it helps thicken and stabilize the mix. It feels smooth on the skin and rinses clean, though very dry skin may notice some tightness after washing.

Good for

Suits people who like simple, traditional formulas, such as bar cleansers, shaving soaps and firm sticks, and who don't mind a soap-based feel.

Frequently asked questions

Is sodium stearate the same as regular soap?

Yes, in a sense. Bar soap is mostly made of sodium salts of fatty acids, and sodium stearate is one of those salts. It is a simple, single-fatty-acid soap that has been used in cleansing products for a long time.

Is sodium stearate safe for sensitive skin?

It is generally well tolerated, but soaps can be drying for some people. If your skin feels tight, choose a formula with added moisturizers, and patch test new products first.