How long does sunscreen last?

Like many other cosmetic products, sunscreen has a limited shelf life. How long sunscreen lasts depends on various factors. These include:

• Date of manufacture
• Ingredients
• Storage conditions

Usually, the shelf life of sunscreen is indicated on the tubes or bottles with the symbol of an opened can, next to which there is an indicator of shelf life such as ”12 M”. This means that the sunscreen will keep for 12 months after opening. Up to this point, the manufacturer guarantees that the sunscreen can be used without hesitation and will not lose its effectiveness. There are also sunscreens whose shelf life is only indicated as six months after opening (i.e. 6 M). Stick to the recommendation and you’ll be on the safe side.

How long sunscreen will keep depends on whether the tube has already been opened or is still unopened. Sunscreen that is still unopened usually has a shelf life of two to three years. But again, it depends on how it is stored and what ingredients it contains. To maximise the shelf life of cosmetic products, you should store them in a cool, dry place protected from light. Increasingly, manufacturers are also putting a specific expiry date on their sunscreen. Usually it is 30 months from the date of manufacture.

Studies suggest that products containing the chemical UV filter octocrylene can form carcinogenic substances when these products are stored for a long time. This can cause the formation of the molecule benzophenone, which can interfere with the body’s hormonal balance. In addition, the old sunscreen, due to its expired UV protection, can cause the skin to be damaged by UV radiation, which can now penetrate unfiltered. This, too, can increase the risk of skin cancer in the long term.

Not only the storage time, but also the storage conditions are relevant for sunscreen. Heat can cause the ingredients in the cream to separate, which also makes it less effective. You should throw away sunscreen if:

• The colour, consistency or smell of the sunscreen has changed.
• The cream has become lumpy.
• The oil has separated from the cream.

Apart from the fact that a cream with such properties no longer provides adequate protection, it can cause skin irritation. Even temperatures in a closed cupboard in warm areas can cause the sunscreen to lose its effect quickly and change in consistency and smell. How long the sunscreen will last can therefore only be given in general terms – as the manufacturers do on their packaging. However, how long you can use sunscreen must be decided individually, depending on the condition of the cream.

It often happens that summer is over at some point and there is still some sunscreen left in the bathroom. This doesn’t have to be thrown away immediately – after all, it may be needed on a sunny day in winter or you may be going on holiday and need sun protection at your warm destination even in winter. If none of this is the case, make sure you store it in a cool, dry and protected place so that you can use it again next spring.

Just keep in mind that sunscreen should be used within six to twelve months of opening. This way, you can be sure that it is still fully effective. If it has been open for longer than this, the active ingredients may have lost some of their potency, meaning that it no longer provides full protection against UV radiation.

If you apply your sunscreen correctly, you should ideally run out of it by the end of the summer, because you’ve always used it generously. To ensure that sunscreen provides full protection, at least the amount that fits on a heaped teaspoon should be applied to the face alone – or better yet, a little more. Cover all parts of your body that are exposed to direct sunlight with enough sunscreen. But remember that clothing does not fully protect against UV radiation either, so it’s best to generously cover your entire body with sunscreen. You should also make sure to refresh your sun protection regularly. It makes sense to reapply it every two to three hours at the latest, as well as after swimming.

To find the best sun protection for your skin type, you first need find out about your individual skin needs and your sun protection requirements. You should reapply your sunscreen regularly and wear clothing that protects against UV radiation. Avoiding the midday heat and moisturising your skin with plenty of body care cream and after-sun products before and after sun exposure can also help to protect your skin. The sunscreen you choose should always offer protection against both UVA and UVB radiation. Both types of radiation can damage the skin – both in the short and long term.

It is important that you wear sunscreen even on cloudy days, because UV radiation can still get through the clouds. Clouds reduce the intensity of the sun’s rays by 10 to 50 percent, depending on the type of cloud – the rest of the radiation continues to pass through unfiltered. If you also pay attention to your sunscreen’s use-by date and only use it when its effectiveness has not been reduced by external factors, then you will be sufficiently protected from the sun.