"The shelf life of an unopened polish can last up to five to eight years, and after opening the polishes last up to two years," Ling Lin says. Forgetting to screw on the top tightly or exposing your bottles to variable temperatures can speed up the expiration process.

“The main problem with using a polish that's been open for more than two years is that it won't yield as good of a user experience. It will probably be thick and hard to put on, and the color might have faded, too,” says Berry. “As polish gets old, it loses the ability to support an even, beautiful application.

The labels and packaging on your nail polish bottles are the best way to determine whether your varnish is ok to use or not. This is due to the 'period after opening' symbol that you can usually find towards the bottom of the bottle in a smaller print.

Ethyl Acetate, Butyl Acetate Nitrocellulose, Isopropyl Alcohol, Polyester Resin, Dibutyl Phthalate, Styrene/Acrylates Copolymer, Stearalkonium Hectorite, Stearalkonium Bentonite, Benozophenone-1, Fragrance.