What Is Amps/Hema Crosspolymer?
Amps/Hema Crosspolymer is a synthetic copolymer made by linking two monomers, 2-acrylamido-2-methylpropane sulfonic acid (often shortened to AMPS) and hydroxyethyl methacrylate (known as HEMA), with a small amount of a crosslinker called N,N′-methylene-bis-acrylamide. This crosslinking turns the loose chains of the two monomers into a stable three-dimensional network that swells in water but does not dissolve. The result is a powder or granule that looks a lot like fine white sand until it is hydrated.
The ingredient was first explored in the late 1980s, when formulators were searching for more efficient ways to thicken water-based skin care without the stickiness common in older gums and cellulose derivatives. Thanks to its reliable thickening power across a wide pH range and its good skin feel it quickly found a place in lotions and gels. Modern production involves mixing the two monomers in water, adding the crosslinker, then triggering polymerisation with heat or a small amount of initiator. After curing, the solid gel is dried and milled into a uniform powder that rehydrates easily when added to a cosmetic base.
You are most likely to see Amps/Hema Crosspolymer in facial moisturisers, gel creams, sheet mask essences, soothing after-sun products, hair styling gels and some colour cosmetics like liquid foundations where a smooth, non-greasy texture is important.
Amps/Hema Crosspolymer’s Cosmetic Benefits/Uses
This ingredient is valued mainly for one key function, yet that single role brings several practical benefits to finished products.
Viscosity controlling: Amps/Hema Crosspolymer swells in water to form a soft, cushiony gel that instantly thickens a formula. By adjusting the amount used, chemists can turn a thin watery solution into a silky serum, a light lotion or a rich cream. The polymer also helps keep oils and active ingredients evenly suspended, which improves stability and shelf life. Because it creates a smooth glide without feeling tacky, it can enhance spreadability and overall user experience.
Who Can Use Amps/Hema Crosspolymer
Because Amps/Hema Crosspolymer is an inert film-forming thickener with no active biological properties, it tends to agree with all skin types including dry, oily, sensitive and mature skin. It has a low molecular weight that keeps it on the surface so it will not clog pores or feel heavy, making it suitable even for acne-prone complexions. There are no known concerns for people with eczema or rosacea as the polymer itself is non-irritating, although the rest of a formula could still pose issues.
The material is fully synthetic and contains no animal-derived components, so it is appropriate for vegans and vegetarians. Its production process also relies on petrochemical rather than animal sources for every feedstock used.
Current safety data show no reproductive or developmental risks linked to topical exposure. That said, anyone who is pregnant or breastfeeding should have their doctor review any new skincare product as an extra layer of caution since overall formula safety, not just this single ingredient, matters.
Amps/Hema Crosspolymer does not absorb UV light nor does it disrupt skin barrier function, so it does not cause photosensitivity. It is also fragrance-free and free of common allergens like proteins, latex or gluten.
Potential Side Effects/Adverse Reactions
Side effects or reactions to topical Amps/Hema Crosspolymer vary from person to person. The points below list potential issues only. When the ingredient is used properly in a well-formulated product most people will experience none of them.
- Mild skin irritation in people already dealing with compromised skin barriers
- Transient redness or itching if the polymer is not fully neutralised and leaves the formula too acidic
- Stinging around the eyes if the product migrates into the ocular area
- Allergic contact dermatitis, though this has only been documented in isolated case reports
- Dryness if the product contains high levels of alcohol, as the polymer itself cannot offset solvent evaporation
If any discomfort, persistent redness or swelling occurs discontinue use and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 0 / 5
Amps/Hema Crosspolymer is a large, water-swelling molecule that sits on the skin surface without penetrating pores or interacting with sebum, so it does not create the kind of film that can trap oil and debris. It is used at low concentrations and is fully soluble or dispersed in the water phase, further limiting any chance of buildup that could block follicles. For these reasons it earns the lowest possible comedogenic score.
Suitable for acne-prone or breakout-prone skin.
No additional factors, such as oxidation or metabolite formation, have been linked to increases in comedogenicity for this polymer.
Summary
Amps/Hema Crosspolymer is primarily a viscosity controller that thickens water-based formulas, stabilises emulsions and improves spreadability by forming a soft gel network when hydrated. Its ability to keep oils and actives evenly suspended helps products stay smooth and consistent from the first pump to the last.
While not as famous as carbomer or xanthan gum, it has a steady following among formulators who want a light, non-sticky feel in modern serums, gel creams and sheet mask essences. Consumers rarely notice it by name yet benefit from its texture-enhancing role in many mainstream products.
Current data show this ingredient to be very safe with a low risk of irritation, sensitisation or pore clogging. As with any new skincare product, a quick patch test is recommended to confirm personal compatibility.