Does sunscreen expire? How long it lasts

Most homes have an old bottle of sunscreen somewhere: in a beach bag, a car door or the back of a bathroom cabinet. It is fair to wonder whether it still works. The short answer is that sunscreen does expire, the rules for how long it lasts are set by the FDA, and heat can shorten that time. This guide explains how to read the date, what to do when there is no date, how to store sunscreen, and how to tell when a bottle has gone bad. It is part of Skinli's guide on how to choose a sunscreen for your face.

The three-year rule

In the United States, sunscreen is regulated as a drug. That brings it under the FDA's rules for nonprescription drugs, and those rules cover expiration dates.

The FDA explains it this way: its regulations "require all nonprescription drugs to have an expiration date unless the manufacturer's stability testing has shown that the product will remain stable for at least three years." Stability testing is the maker's check that the product keeps its strength over time.

The American Academy of Dermatology (AAD) puts the result in one line: "The FDA requires that all sunscreens retain their original strength for at least three years."

So there are two kinds of bottles on the shelf:

What the bottle shows	How long to use it
An expiration date	Until that date, and no longer
No expiration date	Three years from the day you bought it

The FDA says most sunscreens fall into the second group. In its sunscreen questions and answers, it describes most sunscreens as exempt from expiration dating. That means many bottles will have no date printed at all.

What to do with a bottle that has no date

If there is no date, the FDA says a sunscreen "should be considered expired three years after purchase." The CDC gives the same rule: sunscreen without an expiration date "has a shelf life of no more than 3 years."

The problem is remembering when you bought it. The AAD suggests a simple habit: "If you buy a sunscreen that does not have an expiration date, write the date you bought the sunscreen on the bottle." A marker on the cap or the back works well.

If you truly do not know how old a bottle is, the FDA's advice is to throw it away: "If you do not know how old your sunscreen is, discard it."

Why expired sunscreen is a risk

The FDA's list of advice on expiry is short and clear:

• Do not use sunscreen that has passed its expiration date, if it has one.
• Do not use sunscreen that has no expiration date and was not bought within the last three years.
• Discard expired sunscreens "because they may not be safe and effective anymore."

The main risk is weaker protection. The SPF on the label comes from tests the maker runs, and the FDA only requires the product to keep that strength until its expiration date, or for three years when there is no date. After that, nobody has shown the number still holds. The AAD lists using "an expired sunscreen" as one of three common reasons people get sunburned while wearing sunscreen. The other two are not reapplying and using too little.

Heat and sunlight shorten a bottle's life

The three-year rule assumes the bottle is stored as the label says. Every U.S. sunscreen must carry this line under "Other information": "protect the product in this container from excessive heat and direct sun." Federal labeling rules (21 CFR 201.327) require it.

The AAD explains why: "Avoid leaving sunscreen containers under direct sunlight, or in a hot environment such as inside of the car, as this will speed up the rate that sunscreen ingredients break down."

The FDA gives practical steps for days outside. It suggests "wrapping the containers in towels or keeping them in the shade while outside in the heat for long periods of time."

Places that are hard on sunscreen:

• A car in summer, including the glove box and door pockets
• A windowsill or bathroom shelf that gets direct sun
• A beach bag left open in the sun
• A hot garden shed or garage

Places that are easier on it: a cool cupboard at home, a bag kept in the shade, or a cooler at the beach.

How to tell a bottle has gone bad

Check the date first. Then look and feel. The AAD says: "Any obvious changes in the color or consistency of the product mean it's time to purchase a new bottle."

Signs worth acting on:

1. The color has changed, for example from white to yellow.
2. The texture has changed: lumpy, gritty, runny or separated into oil and liquid that will not mix back together.
3. The cream looks or feels different from when the bottle was new in any other way.

A bottle that looks normal can still be past its safe date, so the date or the three-year rule comes first. The look test is a second check.

Mineral, chemical and spray sunscreens

The same rules apply to every type. Mineral sunscreens (zinc oxide or titanium dioxide) and chemical sunscreens both need a date unless the maker has shown they stay stable for three years. Our guide to mineral vs chemical sunscreen compares the two types.

Sprays have one extra concern. The FDA says many spray sunscreens contain alcohol, which is flammable, and flammable products must carry a warning. Keep sprays away from flames and hot places whether or not they are in date.

What about the UK "open jar" symbol?

UK and European sunscreens often show a small open jar with an M and a number. The NHS says this symbol "shows how many months the sunscreen will last once it's been opened." The NHS also says to check that sunscreen "is not past its expiry date." For a U.S. product, the FDA's guidance is the printed expiration date, or the three-year rule when there is none.

Sunscreen bought in another country

The FDA points out that some countries regulate sunscreen differently, for example as a cosmetic, while the United States regulates it as a drug. The FDA says that if you buy sunscreen outside the U.S., "it is important to read the label to understand any potential differences between the product and U.S. products." The expiry marking may look different too. Read whatever date or symbol the package shows, and when you cannot find one, use the FDA's three-year rule from the day you bought it.

Buying a new bottle

When you replace an old bottle, check two things in the store. First, look for a printed date and make sure it is well in the future. Second, read the front for the label words that matter: Broad Spectrum, SPF 30 or higher, and a water resistance time if you will swim or sweat. Our guide on how to choose a sunscreen for your face has the full checklist.

A bottle should run out before it expires

There is another way to look at expiry. The AAD says that if you use sunscreen "every day and in the correct amount, a bottle should not last long."

The correct amount is more than most people expect. The AAD says to use at least 1 teaspoon for the face, which it describes as enough to cover the length of your index and middle fingers. The FDA says an average adult needs at least one ounce to cover the body. Skinli's plan uses two lines of sunscreen, one on each of two fingers, for the face and neck each morning.

At that rate, a face sunscreen used every day is gone in weeks, well before any expiration date. If a tube lasts from one summer to the next, the most likely problem is too little sunscreen each time. Our guide on how often to reapply sunscreen covers the amount and timing.

A quick check before you use an old bottle

1. Is there an expiration date? If it has passed, throw it out.
2. No date? Do you know when you bought it? If it was more than three years ago, or you do not know, throw it out.
3. Was it left in a hot car or in direct sun for long periods? Heat breaks it down faster, so a new bottle is the safer choice.
4. Has the color or texture changed? Replace it.
5. Is it recalled? The FDA says some spray sunscreens were recalled because of benzene contamination, and it recommends not using recalled sunscreens.

For a daily face sunscreen, Skinli's starter acne routine shows where it goes in the morning. If you have acne-prone skin, choose a new bottle labeled non-comedogenic, as our guide to sunscreen for acne-prone skin explains.