If you’ve stashed your sunscreen in a hot car all year, buy a new bottle. Here’s why

Now that summer is almost in full swing, it’s time to start thinking about restocking your sunscreen.

Not only does sunscreen have an expiration date, but it can also quickly degrade in the heat and sunlight. So if it’s been stuck at the bottom of your beach bag or in the back of your car since last summer, it’s time to toss it out and replace with a new one.

When does sunscreen expire?

Sunscreens are one of the only skin care products that are regulated by the FDA for efficacy, so they are required to have an expiration date and to last for at least three years unopened. However, product testing is typically done in a controlled environment and does not account for exposure to high temperatures, moisture or sunlight.

Even if your sunscreen still has a good expiration date, it may not be as effective as it used to be if it has not been stored properly.

Additionally, chemical sunscreens tend to go bad faster than mineral-based sunscreens.

Does expired sunscreen still work?

No, do not use sunscreen that is past its expiration date or that has been left in a hot car or beach bag all season. The active ingredients in sunscreen break down and become ineffective when exposed to heat and light, and moisture can cause mold or yeast to grow. For this reason, I recommend replacing your sunscreen every summer to get the best protection.

How to make sunscreen last longer

It is important to store sunscreen in a cool place away from sunlight so that its active ingredients don’t break down more quickly than they are supposed to. Don’t buy too many bottles ahead of time that you may not use so that you do not end up with wasted sunscreen.

Bottom line

To get the best sun protection, get new sunscreen at the start of every summer and store it in a cool, dry place away from direct sunlight.

There may be new sunscreens coming to the US market soon, so stay tuned for more information in the next few months.

I’m still on sabbatical and no longer run Baumann Cosmetic Institute, so please follow @SkinTypeSolutions on social media, or visit LeslieBaumannMD.com if you have questions.