Methoxy PEG-100
molecular structure · PubChem
AKA: Methoxypoly(Ethylene Glycol) 100, Polyethylene Glycol Methyl Ether 100
Synthetic
Humectant
Solvent
Clean
Poly(oxy-1,2-ethanediyl), .alpha.-hydro-.omega.-methoxy- (100 mol EO average molar ratio)
CAS #
9004-74-4
Form
Liquid
Functions
Humectant
A moisture magnet. Pulls water from the air and deeper skin layers up to the surface to keep skin plump and hydrated.
Solvent
Dissolves other ingredients so they distribute evenly in the formula. Often the invisible "base" everything else is mixed into.
Locks In Moisture
Traditional Use
Synthetic polyethylene glycol derivative developed mid-20th century as a humectant and emollient in cosmetics; designed to improve hydration and product spreadability.
EWG
2
CIR
Safe as used
Pregnancy
Yes
CIR Safety Findings
Not a Sensitizer
medical-approval
all-shades-safe
Regulatory Agencies
Skin Types
●all-skin-types
Best For
Dryness
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory1 listing →
🛡️Safety-assessed2 reviews →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: CosIng · EWG · CIR