PEG-33 Good Polymer Hydration PEG-33 at a glance Lightweight, skin-friendly polymer Helps draw and hold moisture within skin Enhances formulary stability Works as a non-irritating solvent PEG-33 description PEG-33 is the synthetic polymer of ethylene oxide used as a binding agent and humectant. With any PEG (polyethylene glycol) ingredient followed by a number, the lower the number, the lighter the ingredient. Thus, PEG-33 will feel lighter on skin than PEG-200. Among many other PEG-based ingredients, PEG-33 is considered safe as currently used in a broad range of rinse-off and leave-on cosmetics.