Skincare: Before you head to Costco for your acne products, keep this in mind: Most skincare products, like anti-aging creams and serums, moisturizers, and acne treatments are at their most effective for the first year. After 12 months, their active ingredients start to fade until they eventually stop working, says Cromwell.

Lipstick and lipgloss: If you didn’t already know, your mouth is full of germs. That means you need to pay close attention to your favorite lip products. If they begin to smell like “bad breath” (ew!) or chemicals, you should toss them, says Cromwell.

Nail polish: You can wish for your favorite nail polish to last forever, but in reality its lifespan is about six months. However, if you refrigerate your polish, your colors can last up to 12 months, says Hadley. Just don’t mistake that fab red shade for ketchup.