What Is Pei-14M?
Pei-14M is the cosmetic name for a synthetic polymer created by linking many units of aziridine, a small three-membered nitrogen ring. When these rings open and bond together they form polyethylenimine, a clear to slightly hazy liquid or gel that carries the INCI name Pei-14M. Because it is produced in a lab through controlled polymerization, it does not come from a plant or animal source, which makes it popular in formulas that aim to be free of raw materials from living sources.
The polymer first gained attention in industrial processes where its ability to grab onto water and charged particles made it useful in paper making and water treatment. Formulators soon noticed that the same thickening and stabilizing traits could improve the feel and performance of personal care products, so by the late 1990s it began appearing in creams and hair styling gels.
Manufacturing starts with purified aziridine. Under heat and pressure the rings open and link together in long chains. By adjusting the temperature, time and catalysts, chemists can control the average chain length, which determines how thick Pei-14M will be when it is later added to a product.
Today you are most likely to find Pei-14M in lightweight facial serums, creamy lotions, rinse-off masks, hair gels, leave-in conditioners, anti-aging eye creams and even some micellar waters where a hint of body is needed without heaviness.
Pei-14M’s Cosmetic Benefits/Uses
Pei-14M serves one main purpose in cosmetics: it controls viscosity. By swelling slightly in water and forming a network between droplets and particles, it adjusts how thick or fluid a formula feels. This helps prevent a lotion from separating, keeps a gel from running off your hand before you spread it and lends a plush, cushiony glide that can make a product feel more upscale.
Who Can Use Pei-14M
Because Pei-14M mainly acts as a texture enhancer rather than an active treatment, it is generally considered suitable for all skin types including oily, combination, normal and sensitive skin. It does not clog pores or leave a greasy film so acne-prone users usually tolerate it well. Those with very dry skin may wish to pair it with richer emollients because Pei-14M itself does not add meaningful moisture, it just helps keep the product stable.
The polymer is created entirely in a lab from petrochemical feedstocks, with no animal or plant components. This makes it appropriate for vegans and vegetarians who prefer to avoid ingredients sourced from animals.
No studies point to specific risks for pregnant or breastfeeding individuals when Pei-14M is used in topical cosmetics. Still, this is not medical advice and anyone who is pregnant or nursing should review all skincare products with a qualified healthcare provider to be safe.
Pei-14M does not absorb UV light or make skin more reactive to the sun, so it is not considered photosensitizing. It can be used day or night without changing your normal sun protection habits.
Potential Side Effects/Adverse Reactions
Reactions to topical Pei-14M differ from person to person. The following points outline potential side effects even though most people will not experience them when using a well-formulated product.
- Transient skin redness or stinging
- Mild itching or dryness if the formula is unbalanced and draws water away from skin
- Allergic contact dermatitis in individuals already sensitized to polyethyleneimine derivatives
- Eye irritation if the product accidentally gets into the eyes
If any of these reactions occur stop using the product and seek advice from a medical professional.
Comedogenic Rating
Rating: 0 out of 5. Pei-14M is water soluble, forms a light film that rinses away easily and contains no oily or waxy fractions that could block pores. Its large polymer size also limits penetration into follicular openings, which further lowers clogging potential. For these reasons it is considered safe for people who are prone to acne or breakouts. To date there are no published reports linking Pei-14M to increased comedone formation even at the higher concentrations used in hair gels and styling creams.
Summary
Pei-14M is a lab-made polyethylenimine used primarily to control viscosity. By hydrating and intertwining in water it thickens mixtures, stabilizes emulsions and gives lotions and gels a smooth cushiony feel without weighing them down. While not a headline-grabbing active, it shows up quietly in a wide range of skincare and haircare formulas because formulators appreciate its reliable performance and vegan origin.
Current safety data and decades of consumer use point to a low risk profile with only rare cases of irritation or allergy. Still, skin is personal so it is smart to perform a quick patch test when trying any new product that contains Pei-14M.