Polyglyceryl-4 Isostearate

What is Polyglyceryl-4 Isostearate?

Polyglyceryl-4 Isostearate is a synthetic ester formed by combining polyglycerol-4, a chain of four glycerol molecules typically sourced from vegetable oils, with isostearic acid, a branched-chain fatty acid also derived from plant oils like rapeseed or tall oil. This creates a versatile ingredient commonly used in lotions, creams, cleansers, and makeup removers. In formulations, it acts by positioning itself at the oil-water interface, reducing surface tension to stabilize emulsions and prevent separation, while its emollient properties help deposit a light film on the skin for improved spreadability and reduced evaporation of moisture. As a surfactant, it supports mild foaming and dispersion of oils in rinse-off products, contributing to even application and comfortable use across various skincare categories.

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:

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.
Surfactant
Lowers surface tension to enable cleansing, emulsifying, and foaming; central to shampoos, body washes, and many emulsions and micellar systems.
Emulsifying agent
Enables stable mixing of oil and water phases by forming an interfacial film, helping create lotions, creams, and cleansers with consistent texture.

Benefits

Supports smoother skin feel through emollient action that fills surface imperfections.

Helps create stable oil-in-water mixtures for consistent product textures.

Facilitates gentle cleansing by lowering surface tension without harshness.

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 seeking mild emulsifiers in daily moisturizers and lotions.
Those with rare sensitivities to fatty acid esters.
People with normal to dry skin needing added slip and softness.
Individuals allergic to polyglycerol derivatives.
Users of cleansers preferring non-drying surfactant options.
People preferring fully anhydrous or oil-only formulations.

Safety Notes

  • Assessed as low hazard in cosmetic use by safety panels.
  • Minimal irritation potential in typical concentrations.

Frequently Asked Questions about Polyglyceryl-4 Isostearate

What is Polyglyceryl-4 Isostearate made from?

It combines plant-derived polyglycerol-4 and isostearic acid to form a gentle cosmetic ester.

Is it suitable for sensitive skin?

Yes, it shows low irritation potential in formulations from safety reviews.

What products commonly include it?

Found in creams, lotions, and cleansers for emulsifying and softening effects.