You might think now that we are in the depths of winter and warm sunshine is a thing of the past that you can put the sunscreen away until next summer. But that is not the case. UV rays are always present and can damage our skin all year round. One of the best things you can do for your skin is to wear SPF all year, even in winter.

UV rays are made up of many types of light but the two we are most concerned about for skin damage are UVB and UVA. UVB is partially absorbed by the atmosphere and only a small fraction reaches us. But this is the light that causes sun burns, pigmentation and some skin cancers. UVA has much better penetration through the atmosphere and can travel deeper into our epidermis too making it more dangerous. It is responsible for premature ageing and skin cancer. Some UVA light can even penetrate through glass – so consider this if you work by a window or drive regularly. The sun tans we have come to love are actually our melanocyte cells trying to protect our skin from damage by producing more pigment!

Skin ages through two different mechanisms – internally and externally. Internal ageing means that our skin is programmed to age. At a certain stage in our life, we stop producing as much collagen and sebum for example. But our skin also ages because of external factors like sun exposure, diet and habits like smoking. 70% of facial aging is photo-ageing or ageing caused by the sun! What is the point in having skin care routines and using expensive products to delay the signs of aging if we don’t wear SPF all year round? Also, those who use a retinoid in our skincare routine need to be extra vigilant as retinoids make your skin more photosensitive and likely to burn.

So, we understand that SPF is important, but how do we choose the correct one? Firstly, we need to understand the different types of sunscreens available. There are mineral or physical sunscreens made from zinc or titanium dioxide that reflect or scatter UV light and block it from getting through the skin layers. Traditionally these sunscreens were very heavy and left that awful white ghosting effect on the skin. These days nanoparticles are used which allow them to spread better and be more transparent. Often people favour these sunscreens because they are more “natural” but that’s just a marketing hype as zinc and titanium dioxide are highly processed to produce these sunscreens.

The next type is chemical or organic sunscreens – organic referring to the fact that they use organic chemicals and not that it’s due to organic farming practices! These chemicals absorb UV light and examples are homosalate or benzophenone 3. There’s no need to be put off by these strange sounding chemicals, the sunscreen industry is highly regulated, and companies go through rigorous testing to prove the SPF value they claim. Broad spectrum means that the product offers protection from both UVA and UVB.

The best sunscreens usually combine physical SPF with chemical SPF as they work synergistically with each other and allow formulators to create light, easy to use effective formulations. You might see recipes online for homemade sunscreen or hear people talking about plant oils having “natural SPF” values. This is incredibly misleading and dangerous. The SPF from these materials is not consistent and has been shown in many studies not to be reliable. Because SPF does such an important job protecting our skin from damage and even cancer, SPF tests are rigorous and rightly so!

When you apply SPF it’s really important to bear in mind that when companies are testing their sunscreen for SPF values, they always apply 2mg per cm2 – this means that those SPF values on the bottle are dependent on you applying this much too! So, in real terms that means applying around half a teaspoon of sunscreen to your face.

This leads me to the most important part about sunscreen – compliance! It’s all well and good purchasing the sunscreen but you need to wear it every day religiously and you need to apply enough of it. Therefore, it needs to be something you really enjoy using. For the winter period you really will only be wearing it on your face, neck, and maybe hands. So go for something you really like, it can be a lotion, a cream, a serum, even a spray. Make it part of your skincare routine every morning. The steps are as follows, cleanse, hydrate, treat, moisturiser, SPF and then makeup. Make sure you pick something that works in this routine, that you will happily pick up every day and apply.

And finally, sunscreen has a shelf life because by its nature it is a less stable formulation than other cosmetics and using ineffective sunscreen is dangerous. Throw out your sunscreen as soon as it reaches its expiry date and purchase a new one.