Does Sunscreen Expire?

We have all done it. Found a bottle of SPF at the bottom of a bag, squinted at a faded date on the tube, and convinced ourselves it is probably fine.

The truth is, sunscreen does expire, and an out-of-date formula may offer far less protection than the label says. Here is what you actually need to know.

In the United States, sunscreens are regulated as over-the-counter drugs. They generally carry an expiration date unless the manufacturer has shown the product remains stable for at least three years.

Once that date has passed, the labelled level of protection can no longer be relied on.

The active ingredients in sunscreen are the core of the product’s ability to protect the skin from UVA and UVB rays.

To understand more about how UVA and UVB rays affect your skin, read our guide: What Are UVA and UVB Rays?

Over time, even these ingredients can break down within the overall formula as preservatives degrade, emulsions destabilise, and the product’s chemistry shifts.

So, even if you use expired sunscreen, you may not be getting the level of protection indicated on the label, increasing your risk of sunburn.

The formulas start to break down and are undetectable when using.

• Reduced protection: The active ingredients that shield skin from UVA and UVB rays break down over time. The SPF level on the label can no longer be guaranteed, and in some cases the drop in protection is significant.
• Separation: The formula can split, leaving a watery layer on top or an uneven consistency throughout. This means patchy coverage and uneven application, which defeats the purpose entirely.
• Texture changes: Creams may become clumpy or sticky. Sprays can thin out or feel different on the skin.
• Smell and colour shifts: A change in scent or a yellowing of the formula are both reliable signs the product has turned, even if the expiry date has not technically passed yet.
• Skin irritation risk: As preservatives and the formula become less stable, the product may not perform as intended and may become less suitable for use.

If you are in any doubt about your sunscreen, it is time to replace it.

Here are two things to look for when finding the expiry date on your sunscreen.

• The printed expiry date:
  Usually found on the crimped end of a tube, the base of a bottle, or a side panel. It shows when the manufacturer’s stability guarantee ends. If this date has passed, the formula should be replaced regardless of how it looks or smells.
• The PAO symbol:
  This is the open jar icon with a number followed by M, for example 12M. It stands for Period After Opening and tells you how long the product remains effective once the seal has been broken. A 12M means the sunscreen should be used within 12 months of first opening, regardless of the printed expiry date.

Both dates apply. If the printed expiry date is still in the future but you opened the product 18 months ago and it carries a 12M PAO, it is past its effective window.

Quick tip: Write the date you first opened your sunscreen on the bottom of the bottle with a permanent marker. It takes three seconds and saves you from doing the mental maths six months later at the start of summer.

Active ingredients such as Zinc Oxide and Titanium Dioxide, used for UVA/UVB protection in mineral SPF, are a more stable ingredient than many UV filters used in chemical sunscreens.

Filters like Oxybenzone, and Octinoxate are more reactive and susceptible to breaking down when exposed to heat and light over time.

Mineral sunscreen actives such as zinc oxide and titanium dioxide are often considered relatively stable, but the shelf life of a sunscreen depends on the full formula, packaging, and storage conditions, not only the active ingredient.

Any emulsifiers, preservatives, humectants, and other ingredients that make a sunscreen can still degrade. The expiry date accounts for the whole product, not just the mineral actives.

In short: The printed date and PAO symbol still apply for mineral sunscreens, and the advice remains the same. Here’s a quick table to remember:

For a full breakdown of how mineral and chemical sunscreens compare, read: Mineral vs Chemical Sunscreen.

Where and how you store sunscreen has a direct impact on how long it stays effective within its shelf life. A few small habits make a real difference.

• Keep sunscreen in a cool, dark place, away from windows, radiators, and direct sunlight.
• Avoid storing in heat. Sustained heat degrades formula stability faster than almost anything else.
• Keep the lid tightly sealed between uses to prevent oxidation and contamination.
• Do not dilute with water or mix with other products before applying.
• Use the product within its PAO window once opened, and always before the printed expiry date if that comes first.

The honest answer is that using expired sunscreen is a gamble, and the odds are not in your skin’s favor.

The concern is not harm from application. It is that expired sunscreen cannot guarantee full protection, and you have no way of knowing what level of coverage, if any, remains.

You could apply what you believe is SPF 50 and step outside considerably less protected than you think. UV damage builds quietly, even without needing to sunburn. If you’re unsure what SPF means when reading your sunscreen label, check out our guide.

To make sure that your sunscreen is providing the sun protection promised in its labelling, the FDA (U.S Food & Drug Administration) recommends that you:

1. Do not use sunscreen products that have passed their expiration date.
2. Do not use sunscreen products that have no expiration date and were not purchased within the last three years.
3. Discard expired sunscreens because they may not be safe and effective anymore. If you do not know how old your sunscreen is, discard it.

Source: FDA.Gov, 2025

Remember to always check the expiry date, store your SPF correctly, and when it is time for a fresh bottle, PoolBar London has you covered.

PoolBar products are formulated to meet applicable U.S. sunscreen regulatory requirements and are designed to perform consistently throughout their shelf life when stored correctly.