Does Sunscreen Expire?

Yes. Sunscreen expires, and an expired product can give less protection than the SPF on the label as the UV filters degrade. In the US, every over-the-counter drug must carry an expiry date unless stability testing shows it lasts at least three years — so if there's no printed date, treat it as good for three years from purchase.^[1]

Where to find the date. Look for a printed "EXP" date, or a small open-jar symbol (e.g. "12M") showing how many months it lasts after opening. No date printed? Count three years from when you bought it.^[1]

What actually changes. As a formula ages, the UV filters break down and the emulsion can separate — protection drops and texture suffers. Signs it's past its best:

• A change in colour or smell
• The formula has separated, gone watery, or grainy
• It's been loose in a hot bag or car all summer

Heat is the real enemy. Expiry dates assume sensible storage. Kept above about 30 °C, sunscreen degrades much faster — and a car glovebox in summer can exceed 50 °C, slashing effectiveness well before the printed date.^[1] Store it cool and dark; at the beach, keep it shaded or bagged.

The reassuring part. If you use enough, a bottle shouldn't survive long enough to expire. A full-body application is about a shot-glass (≈30 mL), reapplied every two hours outdoors — at that rate one bottle lasts only a few outings.^[2] If a bottle has lasted you two summers, you're almost certainly underapplying, which is a bigger protection problem than the expiry date. Not sure how much to use? See how much sunscreen you actually need.

Bottom line: respect the date, store it cool, watch for changes in look or smell — and when in doubt, replace it. Sunscreen is the cheapest part of sun protection.