You can't keep your favorite nail polishes forever. Sometimes, you have to bite the bullet and throw them out. According to Bustle, here are a few signs that it's time to throw out your nail polish:
1. It Won't Blend
If you shake your nail polish bottle, it should blend together. "Polish should last for up to two years once opened, but if it's still separated and won't blend after a quick shake, toss it."