“Green and blue polishes are gorgeous, but [more] often than not, they leave a stain on your nails,” Goldstein writes in the caption. That’s why she squeezes some whitening toothpaste on each nail and rubs the goop in with a damp cotton pad. 

“Rub the nails until you see no more stain,” she continues. After a few minutes, the polish should lift right off—that’s because most toothpastes contain ethyl acetate, a solvent that can effectively break down the varnish (and it’s also conveniently found in most polish removers).

And because Goldstein uses a teeth-whitening option with added brighteners (she uses this Arm & Hammer tube), that could help further fade some of the stains left on the nail plate. For a sulfate- and fluoride-free dupe, check out this whitening option from Hello, or consult our full list of natural toothpastes

Overall, it seems like a sound hack, as long as you don’t mind gooey fingertips. Another note: You might want to work quickly, as toothpaste can easily dry up into a cement-like paste after a few minutes. If you’re not too fond of toothpaste, other DIY polish removers may work just as well, like this natural vinegar/orange-juice soak. And once your nail plate is scrubbed clean? “Rinse, dry, and moisturize,” Goldstein reminds. 

https://www.mindbodygreen.com/articles/nail-artists-trick-to-remove-polish-stains-with-toothpaste