Gel polish is a nail colour made of acrylate monomers, oligomers and a photoinitiator that hardens under a UV or LED lamp into a cross-linked film, wears for 2 to 3 weeks and is removed by filing and an acetone soak.
Also known as: gel nail polish, gellak, UV gel polish, soak-off gel, shellac
Gel polish looks like lacquer in the bottle but sets by a different route. Regular polish dries as its solvents evaporate. Gel does not dry at all: the lamp, at 365 to 405 nm, triggers a photoinitiator that links the (meth)acrylate monomers and oligomers into a hard, cross-linked film within a minute. The result is high gloss, no drying time and 2 to 3 weeks of wear on fingers or 6 to 8 weeks on toes (Etos). In Dutch it is gellak.
The trade-offs are in removal and exposure. The top has to be filed and the colour soaked in acetone for 10 to 15 minutes; peeling it off takes the top of the nail plate with it and leaves white patches, grooves and thinning that take months to grow out. Acrylate allergy, seen as contact dermatitis around the nails, is a recognised risk. Cleveland Clinic notes that no risk-free nail lamp exists and its dermatologist suggests limiting gel to a few times a year (Cleveland Clinic).
Two EU rules shape the category. The photoinitiator TPO has been banned in cosmetics since 1 September 2025, so any gel sold in the EU is now TPO-free (Cosmetics Business). The monomer HEMA is restricted to professional use, so an at-home gel should be HEMA-free and say so on the label.
Gel is the usual base for salon cat-eye and chrome-powder work, because curing freezes the magnetic pigment or gives the tacky surface the powder needs. Air-dry magnetic lacquer gives the same eye without a lamp and comes off with ordinary remover.