PEG-55
AKA: Polyethylene Glycol 55, Macrogol 55
Synthetic
Humectant
Solvent
Not Clean
Poly(oxy-1,2-ethanediyl), .alpha.-hydro-.omega.-hydroxy- (55 mol EO average molar ratio)
CAS #
25322-68-3
Form
Liquid
Functions
Binding
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
Polyethylene glycol with a molecular weight of approximately 550, developed in the early 20th century. Adopted by the cosmetics industry from the 1950s as a humectant and solvent for creating stable, hydrating formulations.
EWG
4
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
General
Pregnancy & Breastfeeding Safe
Yes
The paper trail
🔬Peer-reviewednone on file
⚖️Regulatory1 listing →
🛡️Safety-assessed1 review →
Counts, not a verdict. A listing isn't a study. The trail, you decide.
Verified Jun 2026
Data: CosIng · EWG · CIR