There are a few telltale signs.

If you bitterly toss mostly full bottles of sunscreen at the end of the summer, you'll be happy to learn that it's possible to get a couple more seasons—or even years—out of that tube. Sunscreen should remain effective for three years from the date of manufacture, though it could expire sooner if you're not careful about how you store it.

It can be pretty easy to spot sunscreen that's expired just by the look of it. It might have a yellow cast, have taken on a different smell, or have changed consistency. Even with brand new bottles, it's important to look out for any of these signs and discard if or when they arise.

Some sunscreens will have a very clear expiration date on the bottle or tube, while others might take a little more sunscreen know-how in order to decipher what the seemingly random set of numbers mean. Banana Boat is one brand where things aren't quite so intuitive. While, like most sunscreens, their products remain effective for 3 years from the manufacture date, properly determining that date is key. A diagram on the brand's FAQ page shows an illustration of a sunscreen tube with a code printed at the top: 15090CF. The 15 stands for the year 2015, while 090 represents day 90 of the year. This means that the bottle would have been manufactured on March 31, 2015. Likewise, if you can't find the expiration or manufacture date on your sunscreen tube, regardless of brand, it's best to do a quick online search to figure out what you're looking at.

All this to say, there is a big difference between three years from the date of purchase and three years from manufacture date. The manufacture date is when the clock starts. Some stores have been known to carry expired sunscreens on their shelves—a fact which GMA uncovered back in 2018.  The rule of thumb is to use your best judgement, even if the bottle is dated. If the color changes, the consistency changes, or the smell changes, it's best to toss it.

How To Safely Store Sunscreen

Though sunscreen should have a 3-year window for use, that's only if the proper care is payed in regard to storing. It's important to keep your sunscreen cool and out of direct sunlight, even when you're at the beach, pool, or lake. The FDA suggests wrapping it in a beach towel, tucking it in your bag, or storing it in your cooler.