Stearic Acid
Stearic acid
- Role
- A fatty acid that stabilises emulsions and helps build a firm texture.
- Catalog formulas
- 4
- Type
- Texture
- Verified
- 09.11.2026
What does this ingredient do in an antiperspirant?
A saturated fatty acid (octadecanoic acid); its salts and esters are called stearates. It is obtained by saponifying plant and animal fats and is also used as the food additive E 570. INCI functions: emulsifier, emulsion stabiliser, cleansing and refatting agent, fragrance.
Part of a system, not a label in isolation
In the catalogue it appears in sticks, where it helps stabilise the base and hold its consistency. It does not reduce sweating.
The CIR concluded that Stearic Acid is safe in the present practices of use (1987 assessment, conclusion reaffirmed in 2005); the CIR summary table lists use concentrations above 50%.
According to the CIR summary, animal reactions to stearic acid ranged from moderate irritation to none, while in clinical studies it was not an irritant, sensitiser or phototoxin. An individual reaction to the finished product is possible.
Not to be confused with Stearyl Alcohol: stearyl alcohol is a fatty alcohol, while stearic acid is a fatty acid. Sodium Stearate is its sodium salt and a separate INCI name.
Products containing Stearic Acid
Links are based on the complete published INCI list for the exact product version.
Sources
The conclusions apply to the stated conditions and jurisdictions, not automatically to every concentration or product.
- EU CosIng: Stearic Acid Supports: INCI functions, substance identity
- COSMILE Europe (Cosmetics Europe): Stearic Acid Supports: substance description
- CIR: Quick Reference Table (summary of conclusions, 2014) Supports: safety conclusion, use concentrations
- CIR: Safety Assessment of PEG Diesters as Used in Cosmetics (2015) Supports: irritation and sensitisation