murphyCaprylyl Methicone
AKA: 17955-88-3, 1, 3, 5, 5-Heptamethyl-3-octyltrisiloxane, Caprylyl trisiloxane, Trisiloxane, Heptamethyloctyltrisiloxane, Octylheptamethyltrisiloxane, SILSOFT 034
Synthetic
Emollient
Skin Conditioner
Synthetic
Clean
OriginDerived from plant-based oils such as coconut or palm kernel oil through hydrocarbon extraction. Synthesized by attaching methyl silicone chains to caprylyl alcohol through siloxane bond formation.
The Expert Panel for Cosmetic Ingredient Safety concluded that the following 30 dimethicone, methicone, and substituted-methicone polymers are safe in cosmetics in the present practices of use and concentration described in this safety assessment when formulated to be non-irritating, with the exception that the available data are insufficient to make a determination of safety for use of these ingredients in products that may be incidentally inhaled when applied using airbrush devices: Caprylyl Methicone
Formula
C15H38O2Si3
Mol. Weight
334.72
CAS #
17955-88-3
Form
Liquid
State
Liquid
Skin Types
●all-skin-types
Best For
General
Functions
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.
Conditions Skin
Softens & Smooths
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory0 listings
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
EWG
2
CIR
Insufficient
Pregnancy
—
CIR Safety Findings
Not a Sensitizer
2 studies / 2 not sensitizing (CIR 807)
Mixed Skin Irritation Results
2 studies / 1 irritating / 1 not irritating / reactions slight (CIR 807)
Mixed Eye Irritation Results
2 studies / 1 irritating / 1 mixed / reactions slight (CIR 807)
Concentration Guide
Leave-on0.0075–16%
Rinse-off0.22–12%
0%50%100%
CIR reported use · 2020 survey
Regulatory Agencies
Verified Jun 2026
Data: PubChem · CosIng · EWG · CIR