Sunscreens are required by the Food and Drug Administration to remain at their original strengths for at least three years. ... If you buy sunscreen that doesn't have an expiration date, write the date of purchase on the bottle. Throw out the bottle when three years have passed since the purchase date.

What happens when you use expired sunscreen?

For more information, visit our medical review board. Sunscreen expires about 3 years after the date of purchase, or by the expiration date. Expired sunscreen may be less protective against harmful, cancer-causing UV rays from the sun.

How long after expiration date is sunscreen effective?

It should be good for about three years after that date. If you're continuously using a bottle of sunscreen for several days, such as on vacation, and reapplying often, an eight-ounce bottle of sunscreen provides enough coverage for two to three days at the beach for one person.