Polyglyceryl-4 Isostearate
AKA “Isostearic Acid Polyglyceryl Ester, Emollient
Synthetic
Ingredient Facts
Polyglyceryl-4 isostearate
AKA: Isostearic Acid Polyglyceryl Ester, Emollient
Synthetic · Emollient · EWG: 4
Plant-Derived Synthetic
Emollient
Cleanser
Emulsifier
Skin Conditioner
Synthetic
Clean
1,2,3-Propanetriol, homopolymer, isooctadecanoates (1:1) (4 mol glycerol average molar ratio) Science: Origin: Botanic/Natural | Functions: Surfactant - Emulsifying Safety Ratings: CIR: Safe as used
CAS #
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See origin →
Functions
Emulsifying
Forces oil and water to stay mixed instead of separating into layers. The unsung hero holding your lotion together.
Emollient
Fills in the tiny cracks between skin cells to make everything feel smooth and soft. The "silky finish" ingredient.
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Emulsifier
Antioxidant Protection
Reduces Inflammation
Locks In Moisture
Mixes Oil & Water
Traditional Use
Developed as a branched-chain polyglyceryl emulsifier for improved spreadability and skin feel. Designed as an alternative to straight-chain emulsifiers for premium cosmetic formulations.
Skin Types
all-skin-types
Best For
General
Melanin-Rich Skin
Suitable
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe w/Qualifications
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Adverse Events from Emollient Use in Eczema: A Restricted Review of Published Data.
Bhanot A, Huntley A, Ridd MJ
Dermatology and therapy, 2019
Measurement of the biomechanical function and structure of ex vivo drying skin using raman spectral analysis and its modulation with emollient mixture
Biniek K, Tfayli A, Vyumvuhore R, Quatela A, Galliano MF et al.
Experimental dermatology, 2018
Measurement of the biomechanical function and structure of ex vivo drying skin using raman spectral analysis and its modulation with emollient mixture
Biniek K, Tfayli A, Vyumvuhore R, Quatela A, Galliano MF et al.
Experimental dermatology, 2018
Polyglyceryl-4 Isostearate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Polyglyceryl-4 Isostearate/Laurate
European Commission
EU Cosmetic Ingredient Database (CosIng)
Emollients are more than sensory ingredients: the case of isostearyl isostearate.
Dederen JC, Chavan B, Rawlings AV
International journal of cosmetic science, 2012
Polyglyceryl-4 Isostearate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
Restoring Skin Hydration and Barrier Function: Mechanistic Insights Into Basic Emollients for Xerosis Cutis.
Fluhr JW, Muguet V, Christen-Zaech S
International journal of dermatology, 2025
Efficacy of an emollient containing diethylene glycol/dilinoleic acid copolymer for the treatment of dry skin and pruritus in patients with senile xer
Izumi R, Negi O, Suzuki T, Tominaga M, Kamo A et al.
Journal of cosmetic dermatology, 2017
Contact dermatitis caused by polyacrylamide/C13-4 isoparaffin/laureth-7 mix in an emollient cream for atopic skin.
Jaulent C, Dereure O, Raison-Peyron N
Contact dermatitis, 2019
Effect of emollients on UV filter absorbance and sunscreen efficiency.
Sohn M, Amorós-Galicia L, Krus S, Martin K, Herzog B
Journal of photochemistry and photobiology. B, Biology, 2020
Effect of emollients on UV filter absorbance and sunscreen efficiency.
Sohn M, Amorós-Galicia L, Krus S, Martin K, Herzog B
Journal of photochemistry and photobiology. B, Biology, 2020
Effect of emollients on UV filter absorbance and sunscreen efficiency.
Sohn M, Amorós-Galicia L, Krus S, Martin K, Herzog B
Journal of photochemistry and photobiology. B, Biology, 2020
Efficacy of a Rhealba® Oat Extract-based emollient on chr...
J Theunis, H Chaussade, O Bourgeois, V Mengeaud
Journal of the European Academy of Dermatology and Venereology : JEADV, 2017
Efficacy of a Rhealba® Oat Extract-based emollient on chr...
J Theunis, H Chaussade, O Bourgeois, V Mengeaud
Journal of the European Academy of Dermatology and Venereology : JEADV, 2017
Efficient Development of Green Emulsifier/Emollient-Based Emulsion Vehicles: From RSM Optimal Experimental Design to Abridged In Vivo Assessment.
Vukašinović M, Savić S, Cekić N, Ilić T, Pantelić I et al.
Pharmaceutics, 2023
Efficient Development of Green Emulsifier/Emollient-Based Emulsion Vehicles: From RSM Optimal Experimental Design to Abridged In Vivo Assessment.
Vukašinović M, Savić S, Cekić N, Ilić T, Pantelić I et al.
Pharmaceutics, 2023
Efficient Development of Green Emulsifier/Emollient-Based Emulsion Vehicles: From RSM Optimal Experimental Design to Abridged In Vivo Assessment.
Vukašinović M, Savić S, Cekić N, Ilić T, Pantelić I et al.
Pharmaceutics, 2023
Efficient Development of Green Emulsifier/Emollient-Based Emulsion Vehicles: From RSM Optimal Experimental Design to Abridged In Vivo Assessment.
Vukašinović M, Savić S, Cekić N, Ilić T, Pantelić I et al.
Pharmaceutics, 2023
Efficient Development of Green Emulsifier/Emollient-Based Emulsion Vehicles: From RSM Optimal Experimental Design to Abridged In Vivo Assessment.
Vukašinović M, Savić S, Cekić N, Ilić T, Pantelić I et al.
Pharmaceutics, 2023
Verified Feb 2026
Data: CosIng · EWG · CIR