10 Signs Your Skincare Has Expired

Even without a PAO date, your products will usually tell you when they've gone off. Here are ten signals worth paying attention to.

1. A sour, metallic, or generally off smell. Fresh formulas smell like their ingredients; expired ones start to smell like nothing you want on your face.

2. Separation you can't shake back together. If oil and water have permanently divorced, the emulsion has broken and the product isn't stable anymore.

3. A colour change. Vitamin C serums that turn from clear to deep orange or brown have oxidized. They're not dangerous, but they won't work either.

4. Grainy or lumpy texture in what used to be a smooth cream.

5. A film of water sitting on top of a moisturizer or mask.

6. Sunscreen that suddenly stings or feels different on application — SPF filters lose stability past their expiry.

7. Mascara or liquid eyeliner that clumps, dries out, or smells like an old crayon (please, three to six months maximum).

8. Lipsticks or balms with a chalky bloom on the surface.

9. Any product that irritates skin it never used to irritate.

10. A jar you honestly can't remember opening. If you can't date it, and CosmeShelf isn't tracking it, treat that as the sign.