Does Sunscreen Expire? The FDA's 3-Year Rule, Explained
That half-used bottle from last summer might still protect you — or might not. The FDA has a clear stability standard that settles the question.
FDA regulations require sunscreens to retain their original strength for at least three years; a product without a printed expiration date should be treated as expired three years after the date of purchase, and heat exposure speeds up the breakdown of the active ingredients.
The FDA advises that because sunscreens must remain effective for at least three years, an undated bottle should be discarded three years after purchase, and that exposure to high temperatures can degrade the product before then.
Questions we get a lot
How long does sunscreen last?
FDA regulations require sunscreens to keep their original strength for at least three years. If your bottle has a printed expiration date, follow it. If it doesn't, the FDA advises treating it as expired three years after you bought it.
Does heat actually ruin sunscreen?
Yes. The FDA notes that heat exposure can degrade sunscreen and shorten its effective life, which is why leaving a bottle in a hot car or in direct sun is a bad idea. Store it in a cool place, and consider wrapping it in a towel at the beach. Visible changes like separation or an off smell are signs to replace it.
Is expired sunscreen dangerous or just weaker?
The main risk is reduced protection: degraded actives may no longer deliver the labeled SPF, leaving you under-protected. Because the FDA requires a minimum three-year stability, using a product well past that window means you can't count on full strength. When in doubt, replace it.
r/SkincareAddiction: 'I found a sunscreen with no expiration date in my drawer — how do I know if it's still good?'