Once you find the perfect cleanser, moisturizer or serum, it can be pretty hard to let it go. However, Glamour Magazine’s beauty blog reports that keeping your skincare products for too long can lead to nasty results – namely irritated skin and breakouts from bacteria buildup. Not to mention, some ingredients lose their potency after a certain time.

While you should always look for an expiration date, not all products have them, so you may need to do a bit of guesswork. Aim to throw out cleansers after a year, serums after 6 months to a year, moisturizers after a year, sunscreen after 6 months to a year and acne treatments after two years, suggests the news source.

Once you’ve cleaned out your stash, stock up on new skin care products. Look for pump dispensers and tubes instead of jars to minimize contamination, and look for opaque packaging that will prevent potent ingredients from breaking down in sunlight.