Does Sunscreen Expire? Storage, Expiry and How Much to Apply

You find last summer’s sunscreen at the bottom of your beach bag. It looks fine, it smells fine, and there’s half a bottle left. Can you still use it? Does sunscreen expire? Yes, it does, and an old or badly stored bottle may not protect you the way the label says. But expiry is only half the story. Using too little, or forgetting to reapply, can leave you just as unprotected.

Here’s how to tell whether your sunscreen is still good, how to store it, and exactly how much to apply.

Key takeaways

• Sunscreen expires. In the US, one with no expiration date should be treated as expired three years after purchase.
• Throw it out if the color, smell or texture has changed, or if it has separated.
• Keep it out of direct sun and hot cars, since heat breaks ingredients down faster.
• Use at least 1 teaspoon for your face and about 1 ounce (a shot glass) for exposed skin on your body.
• Reapply every two hours, and straight after swimming, sweating or towel drying.

Does sunscreen expire?

Yes. Over time, the ingredients that protect your skin break down. The American Academy of Dermatology (AAD) recommends tossing sunscreen once it expires, because its active ingredients no longer protect you. AAD dermatologist Cynthia Bailey tells the story of her husband using the previous year’s expired sunscreen for a day of gardening. He reapplied as recommended and still ended up badly sunburned.

An old bottle can cause other problems too. AAD dermatologist Dara Spearman explains that expired sunscreen may break down and irritate your skin, or even cause an allergic reaction, and that mold or bacteria can grow in the container over time.

How to find your sunscreen’s expiry date

In the US, sunscreens are regulated as over-the-counter drugs. The U.S. Food and Drug Administration (FDA) requires them to show an expiration date unless the manufacturer’s testing shows the product stays stable for at least three years. So:

• If there’s a date on the bottle, follow it.
• If there’s no date, the FDA says to consider the sunscreen expired three years after purchase. The AAD suggests writing the purchase date on the bottle so you don’t have to guess.

In the UK and Europe, where sunscreens fall under cosmetics rules, the NHS advises checking your sunscreen isn’t past its expiry. Look for the symbol of an open jar with an M and a number, which tells you how many months the sunscreen lasts once opened. If you’re not sure how to read it, here’s what the open-jar PAO symbol means.

How to tell if sunscreen has gone bad

Sunscreen can spoil before its date, especially if it’s been stored somewhere hot. The AAD recommends replacing it if you notice:

• An obvious change in color
• A different or foul smell
• Separation, such as an oily layer sitting on top of a thicker one
• A dry, flaky consistency

When in doubt, throw it out. A new bottle costs far less than a bad sunburn.

How to store sunscreen so it keeps working

Heat is sunscreen’s biggest enemy. The AAD warns that leaving sunscreen in direct sunlight or somewhere hot, like inside a car, speeds up how quickly its ingredients break down. The FDA suggests wrapping containers in a towel or keeping them in the shade when you’re outside in the heat for a long time.

A few easy habits help:

• Keep sunscreen in a cool, shaded spot in your bag, not on the dashboard or in the glovebox.
• Close the cap tightly after each use.
• Write the purchase or opening date on the bottle with a permanent marker.
• Start the season with a fresh check of every sunscreen in the house, including the ones in beach bags and gym lockers.

How much sunscreen to apply

Most of us don’t use nearly enough. The NHS points out that if sunscreen is applied too thinly, the protection it gives is reduced. Here’s what dermatologists recommend:

• Face: at least 1 teaspoon (about 5 ml). The AAD describes it as enough to cover the length of your index and middle fingers.
• Body: about 1 ounce (roughly 30 ml, or enough to fill a shot glass) to cover skin not covered by clothing, according to the AAD and FDA. You may need more depending on your body size. The NHS suggests around 6 to 8 teaspoons if you’re covering your entire body.

Don’t forget the easy-to-miss spots: ears, neck, the tops of your feet, and your scalp if your hair is thinning (or wear a wide-brimmed hat). For your lips, the AAD recommends a lip balm with SPF 30 or higher.

If a bottle seems to last you forever, it’s worth checking that you’re applying enough.

How often to reapply sunscreen

Sunscreen doesn’t last all day. Follow these rules from the AAD and NHS:

• Apply before you go outside. The AAD says it takes about 15 minutes for your skin to absorb sunscreen and protect you.
• Reapply at least every two hours while you’re outdoors.
• Reapply straight after swimming, sweating or towel drying, even if your sunscreen is “water resistant”.

In the US, water-resistant sunscreens must say whether they stay effective for 40 or 80 minutes while swimming or sweating. The FDA is clear that there’s no such thing as “waterproof” sunscreen, because all sunscreens eventually wash off.

Cloudy days count too. The AAD notes that up to 80% of the sun’s harmful UV rays can get through clouds.

Which sunscreen to choose

The AAD recommends a broad-spectrum sunscreen (protecting against both UVA and UVB) with SPF 30 or higher that’s water resistant. In the UK, the NHS recommends at least SPF 30 and a UVA star rating of at least 4 stars. Sunscreen works best as part of a team with shade, a hat, sun-protective clothing and sunglasses.

Sun protection for every skin tone

Sunscreen isn’t only for people who burn easily. The AAD and NHS both stress that people of all skin tones can get skin cancer. If you’re prone to dark spots or uneven tone, the AAD notes that visible light can increase skin darkening, particularly for people with darker skin tones, and that tinted sunscreens containing iron oxide can help protect against it. Choosing a tint that matches your skin tone can also help you avoid the white cast some sunscreens leave behind.

For babies under six months, the FDA and AAD recommend keeping them out of the sun and using shade and protective clothing instead of relying on sunscreen. Ask your pediatrician if you’re unsure.

Never lose track of your sunscreen again

Skinchii makes sunscreen one less thing to remember. Add each bottle to your shelf with its opened date and printed expiry or period after opening, and Skinchii reminds you before it expires. Low-stock alerts nudge you to restock before you run out. Build a morning routine with an SPF step, or a midday “reapply” routine with its own reminder. Every Skinchii morning routine template includes an SPF step, too. Skinchii is coming soon to iOS and Android. Join the waitlist and let your beauty buddy look after the details.

Sources

• U.S. Food and Drug Administration: Sunscreen: How to help protect your skin from the sun
• American Academy of Dermatology: Sunscreen FAQs
• American Academy of Dermatology: How to apply sunscreen
• American Academy of Dermatology: When to toss your makeup and sunscreen
• NHS: Sunscreen and sun safety

This article is for general information and isn’t medical advice. For persistent skin concerns, see a board-certified dermatologist.