How long does sunscreen last? When does it expire?

If you just found a bottle of sunscreen that you bought in anticipation of Y2K, it’s probably not a good idea to use it. After all, although sunscreen has a shelf life for a while, a quarter of a century is a little or perhaps a lot too long. The effectiveness of sunscreen will eventually deteriorate over time and eventually no longer provide sufficient protection for your skin against the sun’s ultraviolet rays. That’s why you shouldn’t use sunscreen that you found in a time capsule. The question then is: what do you do when you have a container of sunscreen on your shelf or in your Kardashian hope chest?

The first thing you should do is look for an expiration date on the container. Since there is no mandate from the U.S. Food and Drug Administration (FDA) to put such a date on sunscreen packages, you could be looking for a long time. However, if you find an expiration date and today’s date is already past that date, then it is better to get rid of the sunscreen. And throwing it away doesn’t mean your partner has to use it. Throwing it away means throwing it away so that no one will accidentally use it. You don’t want someone to mistakenly believe that he or she is protected from UV rays that can damage the skin and lead to several types of skin cancer.

If you cannot find an expiration date, you can assume that the sunscreen will last up to three years after the date of purchase. That’s because the FDA requires manufacturers to ensure their sunscreen retains its original strength at least three years. ‘At least’ means that in theory the sunscreen could remain effective for many years longer. But it’s not a good idea to play sunscreen roulette here. Once you cross the three-year mark and there is no expiration date, all bets are off.

All of the above assumes that the sunscreen was stored under reasonable storage conditions. Although opening the bottle will not accelerate the deterioration of the sunscreen, exposure to heat and sunlight can. Therefore, if someone says, “You can use this sunscreen even though I’ve been burning the container once a week for the past year,” you might want to spend the extra money to buy a new bottle. It may not be clear whether the sunscreen has been changed by the environment. It’s not like sunscreen will automatically start to look like spaghetti sauce when replaced. So if the sunscreen has been left outside for a while, in the trunk of a car or on a stone pizza oven, it is better to throw it away.

Of course, if the sunscreen has changed color, texture or scent, do not use it, regardless of when the expiration date has been reached and how safely it has been stored. For example, if your sunscreen smells like fish (assuming you didn’t buy that special Sushi Sunscreen), something strange may have happened.

Unless you have a habit of hoarding containers of sunscreen, having a container that you’ve kept for a long time could be a sign that you’re not using enough sunscreen. Normally, every time you apply sunscreen to your face and body, you should use at least one shot glass, which is about 30 milliliters. You may even end up using more, as using too much sunscreen isn’t a problem unless you find yourself sliding all over the place because you’ve become too slippery. If you empty the container with one shot every time, you will probably blow through the container within a year.

In general, it’s better to be careful when applying sunscreen and buying new containers of the stuff. Since you don’t necessarily have to take out a loan to buy another bottle of sunscreen, you don’t want to gamble with something that may or may not work.