Phytosteryl Isostearate

Benefits
Hair ConditioningSoftening

What is Phytosteryl Isostearate?

Phytosteryl Isostearate is an ester derived from phytosterols—naturally occurring plant sterols similar to cholesterol, sourced from vegetable oils—and isostearic acid, a branched-chain fatty acid produced from oleic acid. Commonly used in hair care products like conditioners and styling aids, as well as skin moisturizers and lotions, it functions as an emollient and conditioning agent. Upon application, it spreads evenly to form a thin, non-greasy film over the skin and hair surface. This barrier reduces water loss, minimizes friction between hair strands or skin cells, and enhances tactile qualities such as suppleness and luster. Its branched structure provides stability and compatibility in formulations, allowing effective delivery without heaviness.

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:

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

Enhances hair softness, shine, and ease of combing by coating strands.

Maintains skin smoothness and flexibility through emollient action.

Forms a protective film to support moisture retention on skin and hair.

Who It's For

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

Who May Benefit Who Should Avoid
Individuals with dry or rough skin seeking emollient hydration.
Those with known allergies to plant sterols or fatty acid esters.
People with frizzy or unmanageable hair needing conditioning.
People experiencing irritation from similar emollient ingredients.
Users preferring lightweight, non-oily texture enhancers in products.
Individuals sensitive to branched-chain fatty acids in cosmetics.

Safety Notes

  • Considered low hazard in cosmetic concentrations by safety assessments.
  • Non-comedogenic, unlikely to clog pores based on available data.

Frequently Asked Questions about Phytosteryl Isostearate

What does Phytosteryl Isostearate do in products?

It acts as a conditioning agent, softening skin and hair by forming a protective, moisturizing film.

Is it safe for sensitive skin?

Generally low irritation potential, suitable for most, but patch test if concerned about ester sensitivities.

Does it help with dry hair?

Yes, it improves manageability and shine, reducing friction for softer, smoother strands.