Beyond HEMA: What Changed Inside Nail Cosmetics Between 2023 and 2026

"HEMA-free" has become a marketing claim stamped across nail polish and gel displays in response to a wave of allergic contact dermatitis linked to the ingredient. A new study in Contact Dermatitis puts a number on how much the underlying formulations have actually changed, by comparing the same products' ingredient lists three years apart rather than relying on what the label promises.

Norbertus A. Ipenburg, Anton C. de Groot, and Thomas Rustemeyer searched online listings for 394 nail cosmetics in 2023, then returned to find 127 products that matched by brand and commercial name in 2026. Tracking identical products over time, rather than comparing two unrelated snapshots of the market, let the researchers isolate reformulation from simple shifts in which products happened to be popular or available.

The headline finding: 2-hydroxyethyl methacrylate (HEMA) listings fell from 65.4% of the matched products to 16.5%, a 75% drop, while Di-HEMA trimethylhexyl dicarbamate (Di-HEMA TMHDC) fell from 27.6% to 7.1%, a 74% drop. Both are among the most common causes of allergic reactions to nail cosmetics, so a decline of that size across matched products suggests the HEMA-free trend reflects real reformulation rather than labeling alone.

But the ingredient story does not end with HEMA. Trimethylolpropane triacrylate and urethane acrylate dropped by 63% and 54%, respectively, while benzyl methacrylate, urethane methacrylate, and trimethylolpropane trimethacrylate rose by 100% to 225%. The authors frame this as a broader shift in the (meth)acrylate chemistry of nail products, not a single-ingredient swap, which matters for dermatologists trying to patch-test patients against the right suspects as formulations move.

The study also tested a narrower, practical question: when HEMA or Di-HEMA TMHDC does remain in a product, is it confined to professional-use items applied by trained technicians, or does it reach consumers directly? Among 24 matched products still containing one or both ingredients, 4 (16.7%, or 3.1% of all 127 matched products) appeared to be marketed straight to consumers online without any identifiable professional-use restriction.

The authors describe that gap as small in absolute terms but still a documentation question worth flagging, since it concerns whether an allergen with well-established sensitization risk is reaching people without the safeguards, such as professional application and ventilation, that professional-use products assume. Ingredient lists, the researchers note, remain the only way to check that assumption against what a product's marketing claims.