Stearoyl Sarcosine is a chemical compound primarily used as a surfactant and conditioning agent in hair and skin care products.
The name describes the structure of the molecule:
- Stearoyl refers to the fatty acid derived from stearic acid. This indicates that the compound is a derivative of stearic fatty acid, commonly found in natural sources like cocoa butter and palm oil.
- Sarcosine is a derivative of an amino acid that serves as the base for the compound. Sarcosine derivatives are known for their gentle cleansing properties and for enhancing the softness and silkiness of hair and skin care products.
Origin. Derived from stearic acid, a fatty acid found in many vegetable and animal fats and oils.
Functions of Raw Materials:
Stearic Acid provides the fatty acid component necessary for surfactant formation, contributing to the stability and consistency of the product.
Sarcosine. A derivative of a natural amino acid, it enhances the product's ability to create foam and imparts mildness to the formulation.
Industrial Production Process
- Extraction. Stearic acid is extracted from vegetable or animal fats and oils.
- Reaction. The stearic acid is then reacted with sarcosine to form Stearoyl Sarcosine.
- Purification. The resulting product is purified to remove any impurities and to improve its quality.
- Quality Control. Stearoyl Sarcosine undergoes rigorous quality testing to ensure its purity, effectiveness, and safety.
Form and Color
Stearoyl Sarcosine typically appears as a clear to slightly yellowish, viscous liquid.

What it is for and where
Stearoyl Sarcosine is used in shampoos, conditioners, and other hair care products for its conditioning properties and its ability to reduce frizz and improve combability. It is also used in skin care products for its emollient properties and to improve the texture of the products.
Cosmetics - INCI Functions
Antistatic agent. Static electricity build-up has a direct influence on products and causes electrostatic adsorption. The antistatic ingredient reduces static build-up and surface resistivity on the surface of the skin and hair.
Cleansing agent. Ingredient that cleanses skin without exploiting the surface-active properties that produce a lowering of the surface tension of the stratum corneum.
Hair conditioning agent. A significant number of ingredients with specific and targeted purposes may co-exist in hair shampoo formulations: cleansers, conditioners, thickeners, matting agents, sequestering agents, fragrances, preservatives, special additives. However, the indispensable ingredients are the cleansers and conditioners as they are necessary and sufficient for hair cleansing and manageability. The others act as commercial and non-essential auxiliaries such as: appearance, fragrance, colouring, etc. Hair conditioning agents have the task of increasing shine, manageability and volume, and reducing static electricity, especially after treatments such as colouring, ironing, waving, drying and brushing. They are, in practice, dispersants that may contain cationic surfactants, thickeners, emollients, polymers. The typology of hair conditioning agents includes: intensive conditioners, instant conditioners, thickening conditioners, drying conditioners. They can perform their task generally accompanied by other different ingredients.
Surfactant - Cleansing agent. Cosmetic products used to cleanse the skin utilise the surface-active action that produces a lowering of the surface tension of the stratum corneum, facilitating the removal of dirt and impurities.
Safety
In general, according to a 2001 study, sarcosinates are not irritants and do not sensitize animal or human skin, although they may enhance the penetration of other ingredients through the skin. Therefore, care should be taken when formulating cosmetic products that contain these ingredients in combination with other ingredients. Available data are insufficient to support the safety of acylsarcosines and sarcosinates as cosmetic ingredients in products where they are likely to be inhaled (1).
A more updated study from 2021 finds that these ingredients are safe as used in cosmetics when formulated to be non-irritant, but they should not be used in cosmetic products in which N-nitrous compounds may be formed (2).
![]() | ![]() |
Molecular Formula C21H41NO3
Molecular Weight 355.6 g/mol
CAS 142-48-3
UNII AJ0EI4K4R8
EC Number 205-539-7
DTXSID8059716

