What Is Hydroxyethyl Imidazolidinone?
Hydroxyethyl Imidazolidinone is a synthetic molecule formally known as 1-(2-hydroxyethyl)imidazolidin-2-one. It belongs to the imidazolidinone family, which features a five-membered ring containing two nitrogen atoms and a carbonyl group, plus a hydroxyethyl side chain that boosts its affinity for water. Chemists first explored this class of compounds in the mid-20th century while searching for stable water-binding agents for industrial uses. By the late 1990s personal care formulators recognized that Hydroxyethyl Imidazolidinone’s strong ability to hold moisture could improve skin feel in lotions and creams, leading to its adoption in cosmetics.
The ingredient is typically produced through a controlled reaction between ethylene oxide and imidazolidinone under moderate heat and pressure. The process yields a clear liquid or crystalline solid that dissolves easily in water, simplifying its incorporation into modern formulations.
Today Hydroxyethyl Imidazolidinone appears in a range of products, including lightweight facial moisturizers, sheet masks, hydrating serums, after-sun gels, hair conditioners and makeup designed to resist drying out during wear.
Hydroxyethyl Imidazolidinone’s Cosmetic Benefits/Uses
In skin and hair care formulas Hydroxyethyl Imidazolidinone serves one primary role.
Humectant: The molecule attracts and binds environmental water, drawing it to the skin or hair surface. This boosts immediate hydration, softens texture, supports a smoother appearance and can enhance the spreadability of other active ingredients by maintaining an optimal water phase within the product.
Who Can Use Hydroxyethyl Imidazolidinone
Because it is a lightweight humectant that does not add oil or heavy film, Hydroxyethyl Imidazolidinone is generally suitable for all skin types including dry, oily, combination and mature skin. Those with very sensitive or compromised skin barriers can usually tolerate it as well since the molecule has a low irritation profile, though individual reactions are always possible.
The ingredient is manufactured synthetically from petrochemical feedstocks so it contains no animal-derived materials, making it acceptable for vegans and vegetarians. Brands that follow cruelty-free standards can incorporate it without conflict.
Current safety data show no specific risks for pregnant or breastfeeding women when the ingredient is used at the concentrations normally found in cosmetics. That said, this is not medical advice and anyone who is pregnant or nursing should run any skincare products past a qualified healthcare provider to be on the safe side.
Hydroxyethyl Imidazolidinone does not cause photosensitivity and will not increase the skin’s vulnerability to sunburn. It can be worn day or night and pairs well with sunscreen in daytime routines.
Potential Side Effects/Adverse Reactions
Reactions to topical Hydroxyethyl Imidazolidinone differ from person to person. The points below list potential side effects rather than what most users will experience. When the ingredient is formulated correctly and used as directed the vast majority of people notice no problems.
- Mild skin irritation such as transient redness or stinging
- Allergic contact dermatitis presenting as persistent redness, itching or small bumps
- Eye irritation if the product accidentally gets into the eyes
- Exacerbation of existing eczema if the individual is already sensitized to imidazolidinone compounds
If any of these effects occur stop using the product and seek medical advice if symptoms do not quickly resolve.
Comedogenic Rating
Rating: 0/5 (non-comedogenic)
Hydroxyethyl Imidazolidinone is entirely water soluble, leaves no oily residue and does not form a film that can block pores. It simply binds water then evaporates or rinses away, which is why formulators consider it non-pore-clogging.
This makes it a safe pick for people who are prone to acne or frequent breakouts.
In very thick or poorly preserved products any ingredient can mix with waxes or oils and raise clogging potential, so overall formula design still matters even when a single raw material scores a perfect zero.
Summary
Hydroxyethyl Imidazolidinone is used mainly as a humectant, meaning it grabs moisture from the air or deeper skin layers and holds it at the surface. By doing so it bumps up hydration levels, smooths texture and helps other ingredients glide evenly across skin or hair.
It never reached the household-name status of glycerin or hyaluronic acid, yet many chemists like it for its light feel and easy incorporation so you will spot it in everything from budget lotions to sheet masks.
Current research and decades of real-world use point to a low risk of irritation or allergy at cosmetic concentrations, and it carries no known health red flags. Still, everyone’s skin is different so it is smart to patch test any new product that contains this or any other active to ensure personal tolerance.