Pei-1750: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: July 1, 2025
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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is Pei-1750?

Pei-1750 is a synthetic polymer made by linking together many units of aziridine, a small nitrogen-containing ring compound. The number 1750 refers to its average molecular weight, which influences how thick it makes a product. First developed in the mid-1900s for industrial uses that needed controlled thickness, it was later adopted by cosmetic chemists looking for a reliable texture builder. Production starts with purified aziridine that is combined under heat and pressure with a catalyst, causing the rings to open and join into a long chain. After the reaction reaches the desired length, the mixture is neutralized, filtered and dried to form a smooth, white powder that dissolves easily in water. Because it is produced in a lab rather than taken from plants or animals, quality and purity stay consistent from batch to batch. You will most often see Pei-1750 in lotions, creams, sheet-mask essences, hair gels, styling creams and rinse-off masks where a silky yet stable feel is important.

Pei-1750’s Cosmetic Benefits/Uses

Pei-1750 mainly serves as a viscosity controlling ingredient. By thickening the water phase of a formula it improves spreadability, gives the product a pleasing body and keeps ingredients evenly dispersed so they do not separate during storage. The result is a smoother application, more uniform coverage and longer shelf life for the finished cosmetic.

Who Can Use Pei-1750

Pei-1750 is generally well tolerated by all skin types including dry, oily and combination skin because it plays a texture role rather than an active treatment. Those with very sensitive or compromised skin may still prefer formulas with minimal additives so checking the full ingredient list is wise.

The polymer is fully synthetic with no animal derivatives which makes it suitable for both vegetarians and vegans.

Current data show no specific risks for pregnant or breastfeeding women when Pei-1750 is used topically in standard cosmetic concentrations. This is not medical advice and anyone who is pregnant or nursing should run new skincare products past a healthcare professional just to be safe.

Pei-1750 does not increase photosensitivity so there is no need for extra sun precautions beyond regular sunscreen habits.

Potential Side Effects/Adverse Reactions

Side effects and reactions to topical Pei-1750 can vary from person to person. The following list covers potential issues but they are unlikely for most users when the ingredient is properly formulated.

  • Mild skin redness, itching or stinging in very sensitive individuals
  • Contact dermatitis if a true allergy to the polymer or trace impurities exists
  • Eye irritation if the product accidentally gets into the eyes
  • Temporary build up or stiffness on hair when used in high hold styling products

If any negative effect occurs stop using the product and seek guidance from a medical professional or pharmacist.

Comedogenic Rating

Rating: 0 / 5. Pei-1750 is a large, water-soluble polymer that sits on the skin surface and is easily rinsed away, so it does not block pores or trap oil. For this reason it is suitable for acne-prone or breakout-prone skin. As with any thickener its comedogenic potential mostly depends on the overall formula rather than the polymer itself.

Summary

Pei-1750 is a lab-made polymer used to control viscosity, meaning it thickens the water phase, stabilises emulsions and keeps pigments or actives evenly suspended. By remaining on the surface it delivers a smoother glide and consistent texture without altering skin biology.

While common in industrial and hair-care settings, Pei-1750 is still a niche choice compared with mainstream thickeners like carbomer or xanthan gum, but formulators appreciate its predictable performance and clear feel.

Current safety data show a very low risk of irritation, allergy or pore clogging when the ingredient is used at cosmetic levels. As with any new skincare product, doing a quick patch test first is a smart extra step.

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