C10-40 Isoalkyl Acid Phytosterol Esters
AKA “Plant sterol ester, Conditioning agent
Acid
Ingredient Facts
C10-40 isoalkyl acid phytosterol esters
AKA: Plant sterol ester, Conditioning agent
Acid · Emollient · EWG: 4
Synthetic
Emollient
Skin Conditioner
Hair Care
Acid
Not Clean
C10-40 Isoalkyl Acid Phytosterol Esters is a complex mixture of esters of phytosterol and C10-40 Isoalkyl Acid
State
Solid
See origin →
Functions
Hair Conditioning
A catch-all term for ingredients that improve how skin looks and feels — softer, smoother, more supple. The workhorse behind most moisturizers.
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.
Viscosity Controlling
Locks In Moisture
Traditional Use
Synthetic derivative combining isoalkyl acids with plant-derived phytosterols, developed in recent decades to combine the emollient benefits of plant sterols with the stability of synthetic compounds.
Skin Types
all-skin-types
Best For
Dryness
Pregnancy & Breastfeeding Safe
Yes
EWG
4
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Status
USApermitted
EUrestricted
JAPANrestricted
CANADArestricted
C10-40 Isoalkyl Acid Phytosterol Esters
European Commission
EU Cosmetic Ingredient Database (CosIng)
Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion.
Dias TC, Baby AR, Kaneko TM, Velasco MV
Journal of cosmetic dermatology, 2008
Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion.
Dias TC, Baby AR, Kaneko TM, Velasco MV
Journal of cosmetic dermatology, 2008
Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion.
Dias TC, Baby AR, Kaneko TM, Velasco MV
Journal of cosmetic dermatology, 2008
Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion.
Dias TC, Baby AR, Kaneko TM, Velasco MV
Journal of cosmetic dermatology, 2008
Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion.
Dias TC, Baby AR, Kaneko TM, Velasco MV
Journal of cosmetic dermatology, 2008
b) As a conditioning agent in rinse-off hair care products, (i.e. benzalkonium chloride with chain lengths ≥ 16 C).
Health Canada
Health Canada Cosmetic Ingredient Hotlist
Verified Jun 2026
Data: CosIng · EWG · CIR