Steardimonium Hydroxypropyl Hydrolyzed Keratin

What is Steardimonium Hydroxypropyl Hydrolyzed Keratin?

Steardimonium Hydroxypropyl Hydrolyzed Keratin is a chemically modified protein ingredient derived from keratin, a fibrous protein naturally found in animal hair, wool, or feathers. Through hydrolysis, the large keratin molecules are broken into smaller peptides for better solubility in formulations. It is further altered by attaching hydroxypropyl groups and a steardimonium chain—a quaternary ammonium group with a stearyl alkyl chain—creating a positively charged, cationic compound. Primarily used in rinse-off hair care products such as conditioners and shampoos, it adheres to the negatively charged hair surface, forming a thin conditioning film. This action smooths raised cuticles, minimizes friction between strands, and neutralizes static charges for improved combability and shine. In skin care formulations like lotions or creams, it acts as a surface conditioner, promoting suppleness by temporarily enhancing the lipid barrier without deep penetration. Its protein-like structure provides compatibility with hair's natural composition.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1 View on EWG →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Antistatic agent
Reduces static electricity and flyaways by improving surface conductivity, enhancing hair manageability and smoothness in conditioners and styling products.
Hair conditioning
Improves softness, shine, and manageability by reducing friction and static; commonly achieved with cationic agents, silicones, oils, or conditioning polymers.
Skin conditioning agent
Maintains skin softness, smoothness, and flexibility.

Benefits

Improves hair manageability by reducing static and flyaways.

Enhances hair softness and shine through surface smoothing.

Supports skin smoothness and flexibility in cosmetic products.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Users with frizzy or unmanageable hair.
Those allergic to animal-derived proteins like wool.
Individuals seeking lightweight conditioning for dry strands.
People sensitive to cationic surfactants.
People wanting added softness in skin moisturizers.
Individuals avoiding non-vegan ingredients.

Safety Notes

  • Rated low hazard by EWG with scores of 1.
  • Non-comedogenic, unlikely to clog pores.

Frequently Asked Questions about Steardimonium Hydroxypropyl Hydrolyzed Keratin

What does this ingredient do in hair products?

It acts as an antistatic and conditioning agent, improving smoothness and manageability.

Is it suitable for sensitive skin?

It carries a low irritation potential based on safety assessments.

Where is it commonly used?

Mainly in conditioners, shampoos, and skin lotions for conditioning effects.