What Is Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer?
Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer is a man-made polymer created from two building blocks: behenyl methacrylate, which comes from the long-chain fatty alcohol behenyl alcohol often sourced from rapeseed or peanut oil, and dimethylaminoethyl methacrylate N-oxide, a small molecule that carries a gentle positive charge. When these two parts are linked together through a process called free-radical polymerization, they form a smooth, wax-like powder that blends easily into creams or sprays.
The material first appeared in the late 1990s when formulators were looking for new styling agents that could resist humidity yet feel light on hair. Its balanced mix of fatty chains and charged groups gave it just the right combination of flexibility and hold. Production begins with converting the raw alcohol and amine into their methacrylate forms, then reacting them in a controlled vessel with heat and an initiator to build long, repeating chains. After filtering and drying, the copolymer is milled into a fine powder ready for cosmetic use.
Today you will most often spot this ingredient in hair styling products such as gels, mousses, aerosols and pomades. It can also appear in conditioning creams, anti-frizz serums, leave-in treatments, sunscreen lotions and even some facial masks where a breathable film or foam control is needed.
Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer’s Cosmetic Benefits/Uses
Below are the key ways this copolymer improves everyday beauty formulas:
- Antifoaming: Keeps excess bubbles from forming during manufacturing and use, giving products a smoother look and feel and helping pumps or sprays work without sputtering
- Film forming: Lays down a thin, flexible layer on skin or hair that locks in moisture, boosts shine and protects against humidity or pollution without feeling sticky
- Hair fixing: Provides light to medium hold so hairstyles stay in place, yet remains easy to brush out and restyle while resisting flaking
Who Can Use Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer
This copolymer is considered friendly for all skin and hair types, from dry and sensitive to oily and acne prone, because it mainly sits on the surface and does not clog pores or disrupt the skin barrier. Those with very reactive or allergy-prone skin might still prefer formulas that use a shorter ingredient list, but the polymer itself is not known to trigger irritation in most users.
The raw materials are plant derived and the production process does not involve animal byproducts or testing, so it is normally suitable for vegans and vegetarians. As always, finished products may vary depending on the other ingredients a brand chooses.
No specific warnings exist for women who are pregnant or breastfeeding. The polymer is not absorbed into the bloodstream in any meaningful amount, and regulatory agencies list it as safe for topical use. That said this is not medical advice and anyone expecting or nursing should ask a healthcare professional before adding new cosmetics to their routine to be on the safe side.
Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer does not increase photosensitivity, so there is no special need to avoid sunlight beyond the usual recommendation to wear sunscreen.
Potential Side Effects/Adverse Reactions
Responses to topical ingredients differ from person to person. The points below represent potential side effects of Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer, but most users will not experience them when products are formulated and used correctly.
- Mild scalp or skin irritation in extremely sensitive individuals
- Contact dermatitis if someone has a rare allergy to methacrylate compounds
- Temporary buildup or dullness on hair when very high concentrations are used or the product is not washed out properly
If you notice itching, redness or any uncomfortable reaction while using a product containing this ingredient, discontinue use and consult a healthcare provider or dermatologist.
Comedogenic Rating
Rating: 1/5
Because it is a large, surface-sitting polymer rather than a free fatty oil, Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer is very unlikely to work its way into pores or feed acne-causing bacteria. The behenyl side chains add slip but are locked into the polymer backbone so they do not behave like traditional pore-clogging oils. In most formulas the ingredient is also used at low levels, further reducing any likelihood of congestion.
Overall this makes it suitable for people prone to acne or breakouts.
One thing to keep in mind is that formulas rich in waxes or heavy silicones may still feel occlusive on very oily skin, so pay attention to the full ingredient list rather than judging this polymer alone.
Summary
Behenyl Methacrylate/Ethylamine Oxide Methacrylate Copolymer is valued in cosmetics for three main jobs: it suppresses unwanted foam during production and use, forms a light breathable film that seals in moisture and adds shine, and gives hair flexible hold that resists humidity. It does all this by combining long fatty chains for slip with gentle positive charges that anchor the polymer to hair or skin, creating a smooth even coating.
While it is not as famous as household names like panthenol or hyaluronic acid, the copolymer has carved out a steady niche in styling mousses, sprays and anti-frizz serums where lightweight performance matters.
Safety data show it is non-sensitizing, non-phototoxic and largely non-comedogenic so most people can use it without worry. Still, everyone’s skin is unique so it is smart to patch test any new product that features this ingredient.