How to Tell If Your Sunscreen Is Expired, According to Dermatologists

When it comes to buying sunscreen, there's a lot to know. For starters, should you be using mineral or chemical formula? Do you need to wear sun protection indoors? And what do the terms 'SPF' and 'broad-spectrum' even mean? But after you've learned what to look for in sunscreen, found your preferred ingredients, and determined which brand, composition, and SPF level is your perfect fit, there's more left to do than apply and reapply, every two hours. There are a slew of sunscreen application mistakes to be aware of, one of them being not knowing that sunscreen expires.

Questions? Us, too. Ahead, we enlisted the expertise of two board-certified dermatologists to help us unpack how, why, and when sunscreen expires, plus how to extend the life of your favorite formula.

Does Sunscreen Expire?

According to board-certified dermatologist Dr. Marchbein, sunscreen does expire. "Like food, sunscreen can go bad and the ingredients can 'spoil,'" she says. And as the ingredients spoil, the sun protective qualities also become less effective, compromising the integrity of the product and leaving you at risk for some serious sun damage. Over time, chemical sunscreens with active ingredients like oxybenzone, octinoxate, octocrylene, and octisalate undergo oxidation—a chemical reaction that alters a substance's composition, changing the formulation from its intended state and efficacy. Mineral sunscreens with active ingredients of either zinc oxide or titanium dioxide degrade over time, lowering the sunscreen's potency.

How Long Does Sunscreen Last?

Generally, "Sunscreens are designed to remain at their original strength for three years," she says, as it is a requirement of the US Food and Drug Administration (FDA).

How to Tell If Your Sunscreen Is Expired

Even if you're not a sunscreen expert, there are a couple of easy ways to tell if your sunscreen is expired. Here's what to look out for:

Check the Expiration Date

The expiration date is a simple way to check how old your sunscreen is. "Sunscreen is considered an over-the-counter drug and is evaluated [by the FDA] for stability, giving it an expiration date." So, most products have the expiry date stamped on the top, side, or bottom of the bottle or the packaging box. If not, or if it has worn off, the three-year rule applies. Just keep in mind, that it's three years past production, not necessarily the date of purchase. Of note, the expiration date also assumes that you have followed the storage directions, which means the expiration date isn't accurate if you've been storing your sunscreen in a garage or space that isn't temperature-regulated.

Check the Smell and Appearance

Your sense of touch, smell, and sight should alert you to whether or not it's a good idea to keep using your sunscreen, or whether it's past its prime. Dr. Marchbein explains that a watery consistency is often the first sign that a sunscreen has gone bad, as the ingredients have separated. Expired sunscreen may smell off, have a slight yellow tint (if the original color was white), or feel grainy. Remember that what might smell or feel okay to use to you might not be the same standard a dermatologist would deem safe.

What Is the Best Way to Store Sunscreen?

Your sunscreen's shelf life and effectiveness also depend on how you store it. "Heat and humidity also accelerate the breakdown of sunscreen, so be sure to keep it at cooler or room temperatures (so storing in your car is not ideal)," Dr. Marchbein says.

As long as sunscreens are properly stored in a dark, room temperature environment, you can technically use them season to season—but Dr. Zeichner says that regardless, it's better to be safe than sorry. "I recommend purchasing new sunscreen every season because you don't want to take any risks when it comes to the sun and your skin," he says.

Does Sunscreen Expire If the Bottle Hasn't Been Opened?

According to the experts, sunscreen products still expire even if they haven't been opened, as the ingredients in the formula will still degrade and oxidize over the expiration timeline.

What Should You Do With Expired Sunscreen?

If you know your sunscreen is expired, toss the sunscreen and buy a new bottle. The same recommendation applies if you can't read the expiration date, are unsure whether the sunscreen has been stored in a temperature-regulated area, or can't tell for certain if the sunscreen is expired based on smell and consistency. Protecting your skin is worth it.

How Bad Is It to Use Expired Sunscreen?

If sunscreen is expired, it not only may feel or smell the same way, but the integrity of its sun-protecting properties may be compromised, which can be downright dangerous.

Dr. Marchbein explains that if this happens, the sunscreen itself becomes less effective, "Which means a significant increase in the potential for sunburns, sun damage/dark spots and risk for skin cancer development." While an expired lotion may not be ineffective, the likelihood is high that if it has started to break down, it won't provide you the protection you need.

The Takeaway

Sunscreen does expire, and you can tell if it's expired by reading the expiration date or spotting a change in consistency or smell. Dermatologists agree that sunscreen can typically last up to three years when stored in a shaded, temperature-regulated room. However, taking risks on whether or not your lotion may be expired isn't worth it. And while we should all be more mindful of reducing waste and excess, this isn't the best scenario to take any chances. We know all too well the dangers of the sun on unprotected skin, so if you're doing the right thing by applying sun protection, it's just as important to be confident that the product will do just that—protect you. When in doubt, throw it out—just like you would with any other over-the-counter or prescription medication or even perishable food item.