Isostearyl Linoleate
AKA “Protachem isl, 127358-80-9, Isostearyl linoleate [INCI], UNII-4778M3HR0N, 4778M3HR0N, 9, 12-Octadecadienoic acid (Z, Z)-, isooctadecyl ester, 12-Octadecadienoic acid (9Z, 12Z)-, RefChem:149998, 16-methylheptadecyl (9Z, 12Z)-octadeca-9, 12-dienoate
Emollient
Ingredient Facts
Isostearyl linoleate
AKA: Protachem isl, 127358-80-9, Isostearyl linoleate [INCI], UNII-4778M3HR0N, 4778M3HR0N, 9, 12-Octadecadienoic acid (Z, Z)-, Isooctadecyl ester, 12-Octadecadienoic acid (9Z, 12Z)-, RefChem:149998, 16-methylheptadecyl (9Z, 12Z)-octadeca-9, 12-dienoate
Emollient · Emollient · EWG: 1
Plant-Derived
Emollient
Skin Conditioner
Clean
9,12-Octadecadienoic Acid (9Z,12Z)-, Isooctadecyl Ester
Formula
C36H68O2
Mol. Weight
532.90
CAS #
127358-80-9
Form
Liquid
See origin →
Functions
Skin Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
Emollient
Fills in the tiny cracks between skin cells to make everything feel smooth and soft. The "silky finish" ingredient.
Locks In Moisture
Traditional Use
A synthetic ester combining isostearyl alcohol with linoleic acid, a naturally-occurring essential fatty acid. Developed to provide skin conditioning and barrier support benefits in modern skincare formulations.
Skin Types
all-skin-types
Best For
Dryness
Pregnancy & Breastfeeding Safe
Yes
EWG
1
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR