Soothing Agents

PEG-33

Reviewed by Emma · Last updated 18 Aug 2026

Lightweight, skin-friendly polymer | Helps draw and hold moisture within skin

Addresses

Dehydration

What Is PEG-33?

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.

Clinical Evidence & References

Published Research

  • Toxicological Research, June 2015, pages 105–136 [https://pubmed.ncbi.nlm.nih.gov/26191379/]
  • International Journal of Toxicology, November 2014, pages 13S–39S [https://journals.sagepub.com/doi/10.1177/1091581814546337]
  • International Journal of Toxicology, May 1997, pages 269–300 [https://journals.sagepub.com/doi/10.1177/109158189701600307]

From the Clinic

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Part of a family

PEG-33 is a variant of PEG-75, the form you will most often see on an ingredients list.

Functions as a humectant to boost skin’s hydration | May also be used as a solvent to mesh ingredients cohesively and enhance formulary texture

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