Isopropyl Isostearate

Concerns
Malassezia Feeding

What is Isopropyl Isostearate?

Isopropyl isostearate is a synthetic ester formed by combining isostearic acid—a branched, saturated fatty acid derived from sources like vegetable oils or tall oil fatty acids—with isopropyl alcohol. This ingredient falls into the category of fatty alcohol esters widely employed in cosmetics for their versatile functional properties. In formulations, it serves as an emollient by depositing a thin lubricating film on the skin, which minimizes surface roughness, enhances slip, and facilitates even product application without a heavy greasy residue. As a binder, it promotes adhesion among solid particles in pressed powders, sticks, and compacts, boosting structural stability and longevity during use. Its skin conditioning role involves supporting the skin's natural barrier to promote suppleness. Commonly found in makeup, lotions, and hair care, its branched structure provides a dry-touch finish ideal for lightweight textures in oil-free or mattifying products.

Comedogenic Rating 5/5 Higher risk of clogging pores
EWG Safety Rating 1 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Binder
Helps hold solid ingredients together to form cohesive tablets, compacts, or sticks, improving pressability, integrity, and wear of the finished product.
Emollient
Softens and smooths skin by filling in surface roughness and improving slip; can also help reduce moisture loss when paired with occlusives and film formers.
Binding
Provides cohesion by helping ingredients stick together, improving the strength and integrity of pressed powders, tablets, or solid bars.
Skin conditioning agent
Maintains skin softness, smoothness, and flexibility.

Benefits

Provides a smooth, non-greasy feel by lubricating skin surface.

Enhances product cohesion in solids like lipsticks and powders.

Supports skin suppleness through mild conditioning effects.

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 skin seeking lightweight softening.
People with oily skin due to high pore-clogging potential.
Users of makeup products for better wear and blendability.
Acne-prone individuals as it rates highly comedogenic.
Those preferring non-oily emollients in lotions or creams.
Those susceptible to malassezia-related issues like fungal acne.

Safety Notes

  • Rated low hazard by EWG with scores of 1.
  • Generally recognized as safe in cosmetic use per expert reviews.

Frequently Asked Questions about Isopropyl Isostearate

What is isopropyl isostearate used for in skincare?

It acts as an emollient to soften skin, binder for product integrity, and conditioner for smoothness.

Is it safe for daily use?

It carries a low safety rating from hazard assessments, suitable in typical cosmetic concentrations.

Why avoid it if acne-prone?

High comedogenic rating and potential to feed malassezia make it unsuitable for oily or breakout-prone skin.