Does sunscreen have an expiration date? If you’ve got a bottle of sunscreen left over from last summer, you may want to think twice before you use it, or you could end up with sun damage. Any unprotected sun exposure can lead to sun damage, whether you have sunburned skin or not, which in turn can lead to premature skin ageing. And if you’ve ever wondered: ‘does sunscreen go out of date?’ We can tell you that it definitely does. But how can you tell if your SPF has expired? How long can you keep sunscreen? Firstly, the formulation will definitely have an expiration date, which is usually stamped on the outside of the pack. This means you can’t rely on out of date sunscreen to protect your skin from those UV rays. But how long does sunscreen last? In general, most SPF products have a shelf life of up to three years. But it’s not always that simple; there are a few other factors to consider too. How to tell if sunscreen has expired? Once you have checked the expiry date, examine how the formulation looks, feels and smells. If the texture has changed (for example: become more watery or grainy), the product is discoloured, or it has a different smell to when you first opened it, the SPF is likely to be ineffective and you should replace it. How long does sunscreen last once opened? This all depends on exactly how and where it has been used. When stored correctly, it should be effective right up until the expiration date. But sunscreen that has been exposed to heat, direct sunlight, bacteria and moisture can degrade faster and will offer less protection – or even none at all. This means it’s always best to store sunscreen in a cool, dark and dry place. So when you are out and about, try wrapping it in a towel to stop sunlight from compromising its effectiveness. Expired sunscreen can’t be relied upon to provide any of that wonderful protection. And if you do decide to use an out of date sunscreen, you may end up with sore, red skin. Plus, you’ll also be exposed to harmful free radicals, which can accelerate skin ageing. How long does unopened sunscreen last? Again it depends on how it has been stored. If your unopened bottle has been sitting in a sunny spot by the side of the pool, or in your car while you’re at the beach, the formulation may be deteriorating even if you haven’t opened it. And finally… If you’re still pondering the question: ‘sunscreen, how long does it last’? Just remember to always check how your SPF looks, feels and smells before applying it to your skin. It is also worth noting that if you are using your sunscreen daily, and as liberally as you should be, it will be used up pretty quickly anyway.