Why Sunscreen is Essential for Skin Health

Estimated reading time: 8 minutes

We all know how important sunscreen is during the summer months, and we’re sure that almost all of us has felt the consequences of forgetting to use sunscreen on a deceptively warm summer’s day.

But, did you know that you need to be wearing sunscreen all year round?

Sunscreen is one of the most important things we can use to keep our skin healthy, but the truth is that most of us aren’t using it correctly. So, let’s dive into why we need to use sunscreen alongside a botanical skincare routine, whether we should buy products with SPFs already included, and what sunscreen we should use to protect our skin.

UVA, UVB, and Broad Spectrum Protection

The energy from the sun reaches the earth as solar radiation or electromagnetic waves. We also call it simply “sunlight” and it’s what keeps us warm and supports life on Earth.

There are several types of radiation and some get completely absorbed by the Earth’s atmosphere (gamma rays, X-rays). However, ultraviolet radiation (UV) only gets partially absorbed by the atmosphere and, although invisible to the human eye, prolonged exposure to it can cause significant negative effects on our skin, eyes and even our immune system.

The UV radiation that does reach the Earth is mainly UVA with a small percentage of UVB:

  • UVA has a shorter wavelength, which means that it’s able to fully penetrate the epidermis (skin’s top layer) and dermis (middle layer), and it can be transmitted through windows. Because UVA can penetrate the dermis, it can go on to affect the production of key proteins like collagen and elastin, which are responsible for premature skin ageing, hyperpigmentation, wrinkles and leathery skin.
  • UVB, meanwhile, has a longer wavelength, so it can only penetrate the epidermis, and it’s typically blocked by windows.

Our skin typically responds to UV radiation by producing more melanin to help our skin absorb it  – which we will recognise as tanning. Unfortunately, both types of UV present a cancer risk.

What is Sunscreen?

In a previous post we discussed how our skin type is largely influenced by genetics. However, as with every aspect of health, what you put into our bodies will always affect our skin. Smoking, for example, is well known for increasing the rate at which our skin develops wrinkles, and alcohol is known to dehydrate our skin.

Multiple studies have shown that a nutrient-rich diet can both increase the health, vibrancy, and barrier function of our skin, as well as reduce the rate at which our skin ages.

Sunscreen is a lotion, cream, solid stick, or gel skincare product that contains chemicals and/or minerals that protect the skin from damage caused by the sun.

Sunscreen products may also contain other skin-beneficial ingredients, and you can often find products with additional emollients or skin-soothing products to help with sunburn.

Every sunscreen product has what’s known as an SPF number. This stands for Sun Protection Factor, and it outlines the amount of solar radiation the product protects us from when it’s applied correctly.

There is a separate rating for UVA protection, which is usually given as a star rating. As part of EU recommendations, you might also see the word UVA in a circle, which means that it provides at least a third of the labelled SPF as UVA protection.

It’s important to understand that SPF is a relative measure, and the amount of protection you’ll get from a particular sunscreen will depend on a variety of factors, like:

  • How much sunscreen you apply

  • How often you reapply sunscreen during the day

  • What time of day you’re using sunscreen

  • What type of sunscreen you use

  • How active you are while wearing sunscreen

In short, SPF isn’t a measure of how long we can spend outside in the sun before you burn. Instead, it’s there to help us compare how much protection each sunscreen will give us and we should always look for both the SPF and UVA rating when buying sunscreen.

Chemical vs. Mineral UV Blocks in Sunscreen

To block UV rays from penetrating our epidermis, sunscreens will always contain a chemical or mineral ingredient – or combination of ingredients – that have UV absorbing or reflecting properties.

Chemical ingredients include compounds like oxybenzone, octocrylene, and homosalate. When you use chemical UV blockers, these are partially absorbed into the skin and protect us from damage via a chemical reaction: they absorb ultraviolet rays and turn the energy into heat that is then dissipated. This type of sunscreen is often advertised as residue-free because the active chemical compounds are more easily distributed and absorbed by the skin.

Mineral ingredients, like zinc oxide and titanium dioxide, sit on the surface of the skin and deflect UV rays. This type of sunscreen, also called physical sunscreen, is typically better for sensitive skin and children, as these ingredients tend to be milder than chemical sunscreen agents.

Mineral ingredients, like zinc oxide and titanium dioxide, are absorbed into the surface layers of our skin and deflect UV rays”

Some sunscreen products may use both chemical and mineral ingredients, so it’s always best to check the label if you have any specific sensitivities.

One of the biggest concerns that people have with sunscreen is the effects of chemical UV blockers when they inevitably end up in our waterways. Specifically, oxybenzone and octinoxate have been found to harm coral reefs, and as such, are now banned in Hawaii, the US Virgin Islands, Palau, Bonaire, and parts of Mexico and Florida.

In response to the new research that shows that even small amounts of chemical sunscreen agents can have devastating effects on coral reefs, there’s been a wave of new brands and existing manufacturers moving towards mineral-only sunscreen formulations.

While it’s not yet understood what effect mineral sunscreen has on the environment, the current scientific consensus is that they are nowhere near as harmful to aquatic life as chemical sunscreen agents.

“We all remember those long summer days, sat on the beach or in our back garden, covered in baby oil and trying to develop a fashionable tan”

How Our Attitudes to Sunbathing Have Changed

Humans have been using a variety of different compounds to shield our skin from the sun, with evidence of sun-protective balms and pastes being found as far back as Ancient Egypt. In Western cultures, in particular, having pale skin was associated with wealth and higher social status until the early 1900s.

However, this all changed in the 1920s when women began to challenge the conservative ideals of the Victorian era. By wearing shorter skirts and sleeves, having a visible tan was a way for women to flaunt their newfound freedom.

The first synthetic sunscreen was first introduced to the market in 1936 by the founder of L’Oreal, but it wasn’t until the 1950s that sunscreen use became more widespread.

Even though the first paper that connected UV radiation to skin cancer was published in 1918, this was largely ignored. At least, that is, until today.

We all remember those long summer days, sat on the beach or in our back garden, covered in baby oil and trying to develop a fashionable tan. Now, those fond memories are likely tainted by the knowledge that each time we sat outside “enjoying” the sun, we were doing irreparable damage to our skin.

The truth is that the trend for tanned skin isn’t going to go away any time soon, despite the increased awareness of skin cancer caused by UV rays.

Which Sunscreen is Best?

We recommend using a dedicated sunscreen product instead of a skincare product with an SPF rating.

More often than not, products like moisturisers and foundations with sunscreen agents are only rated at SPF 15, they are not made to be water or rub-resistant and we’re less likely to apply the amount needed for the SPF to be effective so it’s safer to use a dedicated product.

The British Association of Dermatologists (BAD) recommends using sunscreen that has an SPF of 30 or more if you’re going to be outside for extended periods. Ideally, you want to think of SPF 30 sunscreen as the absolute minimum. 

You should make sure that your sunscreen has a high UVA rating, which you’ll see as either 4 or 5 stars, or with the UVA in a circle label that we mentioned earlier. If a product claims to offer broad-spectrum protection, you should always look for this to double-check the sunscreen can absorb or reflect both types of UV.

Whether you’re following a plastic-free skincare routine, or you want something vegan, cruelty-free or organic, there are so many options on the market that there’s really no excuse to not use sunscreen. Even if you don’t like the standard lotion formula, you can get sunscreen as gels, sprays, sticks, and even foams, so everyone’s sensory needs are accounted for.

How to Use Sunscreen

We recommend using sunscreen as the last step, after you’ve used a cleanser, any serums and moisturiser. This way, you’ll be able to get the full benefits of your other skincare products while protecting your skin from the sun. Apply it liberally and spread it instead of rubbing it, then wait for it to fully dry.

If you choose to wear foundation on top, you can choose one that also has SPF and apply very carefully so you don’t rub the sunscreen underneath. Also, wait a few minutes in-between the application of sunscreen and foundation.

The NHS recommends that you use at least two tablespoons of sunscreen for each full-body application, but you may need more depending on how much skin you have exposed and how much the manufacturer recommends. For the face, aim for 1/2 a teaspoon.

It’s a common misconception that sunscreen only needs to be applied once per day. You should aim to reapply sunscreen at least every two hours, and sunscreen should be reapplied after exercising, swimming, or towel drying, even if the sunscreen claims to be water-resistant or for sports. In addition, make sure you apply sunscreen 30 minutes before you go out, and if you plan on being outside for a while, once again before you leave.

If you’ve still got sunscreen in your cupboard, make sure you check the expiration date. Most sunscreens won’t offer as much protection if any after they’ve passed their shelf life, which is usually 2-3 years.

The most important thing to remember, though, is that using sunscreen doesn’t mean it’s safe to sunbathe and, in particular, use tanning beds. In line with the British Association of Dermatologists, we don’t recommend using sunbeds or sunlamps to get a tan, as these can drastically increase your risk of skin cancer. It’s vital to remember that even with a high-quality sunscreen, you need to take extra precautions when in the sun.

In the UK, this means staying in the shade when the sun is strongest, which is typically between 11 am – 3 pm between March and October. You don’t necessarily need to be inside, but try to stay sheltered by using parasols or awnings with UV protection.

In addition, make sure to cover as much of your skin as you can with loose-fitting clothing, and wear a wide-brimmed hat. You should also wear sunglasses to protect your eyes, particularly if you’re at the beach or in the snow – make sure to look for a UV 400 label, a CE mark, and choose styles that protect the sides of your eyes.

This is particularly important if your risk of skin cancer is particularly high. You’re at high risk if:

  • You have a very light skin tone, and easily burn

  • You have freckles or lots of moles

  • You have a family history of skin cancer, or you’ve had skin cancer before

  • You’re taking immunosuppressant drugs

Vitamin D

Most people wrongly believe that they need to sunbathe to get enough vitamin D. According to Cancer Research UK, if you’ve got a light skin tone, you only need 9 minutes a day in the sun to make enough vitamin D, and only 25 minutes if you’ve got darker skin that rarely burns.

This, of course, fully depends on your skin tone, the time of day, the time of year, and where you are in the world, but it’s worth remembering that you don’t need to spend hours in the sun to get all the vitamin D you need for the day.

Finally, remember to check your skin for any signs of new moles, growths or lumps, or changes to any existing moles or freckles. This is an important habit to get into anyway, but it’s even more crucial if you’ve been spending time in the sun.

Remember that skin care isn’t just about choosing the right products for your skin type, but also about going to your doctor if you notice any drastic changes to your skin.

Sources and further reading:

American Academy of Dermatology Association

Brown, S. Sunscreen wipes out corals. Nature (2008)

Dale Wilson B, Moon S, Armstrong F. Comprehensive review of ultraviolet radiation and the current status on sunscreens. J Clin Aesthet Dermatol. 2012;5(9):18-23.

D’Orazio J, Jarrett S, Amaro-Ortiz A, Scott T. UV radiation and the skin. Int J Mol Sci. 2013;14(6):12222-12248. Published 2013 Jun 7.

How do sunbeds cause cancer? Cancer Research UK

Latha MS, Martis J, Shobha V, et al. Sunscreening agents: a review. J Clin Aesthet Dermatol. 2013;6(1):16-26.


Paul, Charles Norman, The influence of sunlight in the production of cancer of the skin, 1918

Tovar-Sánchez A, Sánchez-Quiles D, Basterretxea G, Benedé JL, Chisvert A, Salvador A, et al. (2013) Sunscreen Products as Emerging Pollutants to Coastal Waters. PLoS ONE 8(6): e65451.

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