“The Best Sunscreen is the One You’re Happy to Use”
Introduction
During the summer months, I’m often asked about which sunscreen is best.
The first thing I advise is that sunscreen is now considered necessary all year round. This includes when you’re sitting by a window or driving, as UVA penetrates glass.
The second thing is to never rely just on sunscreen. Hats, protective sunglasses, staying out of the sun - all of these are important, too.
The Met Office website has a useful UV index showing radiation levels on any given day. Look up the weather for your location & you’ll be given a rating and advice.
How Sunscreens Work
There are different types of UV filters and many sunscreens today contain a combination of both. Both are made of chemicals and they work in slightly different ways.
“Mineral” filters. These use inorganic filters such as zinc oxide & titanium dioxide. In the past these were often referred to as "Physical" filters. They work similarly to chemical filters, by primarily absorbing UV radiation and converting it into harmless heat so that skin cells are not damaged. With Mineral filters, there is also a smaller contribution from scattering and reflection. More recently these filters are often created as "nano", meaning they are engineered into microscopic particles that don't leave that old-fashioned white cast on the skin. While they offer superior cosmetic transparency compared to their non-nano counterparts, some concerns do exist regarding their environmental impact in water systems.
"Chemical” (organic) filters. In this context, 'organic' is a chemistry term. Organic filters are carbon-based molecules. Examples are avobenzone, oxybenzone, octisalate and octinoxate with more recent advances seeing 'new generation' filters with greater photostability & a more sophisticated feel entering the market. An example of these newer filters is "Tinosorb" (Bemotrizinol and Bisoctrizole) which offers some UVA and UVB protection.
How to Choose Your Sunscreen
The decision-making process as to which product to use comes with questions about (in no particular order):
· Level of protection required
· Skin & Eye sensitivity
· Texture & feel on the skin
· Ethics about environmental protection
· Ethics about animal testing
· Health concerns
· Brand reputation
· Cost
Let's go through these in more detail.
Level of Protection
Sunscreen should be at least SPF 30 or SPF 50 and offer broad-spectrum protection, including adequate UVA coverage.
Whatever level of protection we choose, sunscreen's efficacy only lasts for around 2 hours after application, so reapplication is key. Using sunscreen might feel like a chore, but I see it as the most important step in my routine, as UV radiation is the number one cause of skin ageing, not to mention the risks to health.
Sunscreens in the UK & EU come under the scope of "cosmetics" ("medicines"). The UK and EU have a similar precautionary cosmetic safety system. In the US, sunscreens are regulated as "drugs"; in Australia as "therapeutic goods." In Asia the categorisations vary. Laws relating to regulation differ across the globe.
When you choose a product, the packaging should indicate the protection level from both UVA and UVB. If it doesn't (as is often the case with SPF moisturisers) then you can't be sure of its efficacy.
UVB: The SPF number (Sun Protection Factor) indicates protection against UVB, which primarily causes sunburn and contributes to skin cancer. The number measures how much longer skin is protected compared to no sunscreen. Choose SPF 30 or higher. SPF30 filters out about 97% of the sun's rays while for SPF50 it's about 98%.
UVA: UVA protection is more confusing to understand, as there are several different symbols used by different producers. However, protection from UVA radiation is important, as this penetrates deeper into the skin, contributing to ageing, DNA damage and skin cancer. This is how you can understand labelling:
· Originating in the EU, the UVA circle logo ("UVA" letters enclosed in a circle) is a standard marking on sunscreen packaging indicating that the product meets the European Commission's minimum standard for UVA protection. This is based on a measurement of in vivo UVA Protection Factor (UVA-PF) and is relative to the SPF level. SPF30 or 50 with the UVA in a circle is a good indicator that a sunscreen has optimum protection.
· The UVA star rating (1 star to 5 stars ****) pioneered by Boots and common in the UK, shows the level of UVA protection relative to UVB. Therefore a high star rating alone isn't enough. You need at least SPF30 and preferably 5 stars displayed together.
· The PA system (Protection Grade of UVA) originating in Japan & Korea is based on the Persistent Pigment Darkening (PPD) method, which tests how long it takes for skin to tan when exposed to UVA light. This is indicated by the letters PA and then up to ++++ with 4 being the highest protection. The PA system measures the absolute amount of UVA protection. So the PA rating is independent of the SPF rating. SPF30 or 50 alongside PA++++ is preferable.
· In Australia & the US, sun cream shows the words “Broad spectrum” to indicate UVA protection (a similar relative level as in the EU). Each country uses a different way of testing this level. You need SPF30 or 50 along with the wording Broad Spectrum.
Note: If you see the term "broad spectrum" used in general terms, this simply means that a product contains both UVA & UVB protection, but it doesn't guarantee a specific level.
To summarise, to get the best protection look for SPF 30 or 50 plus an indication of high UVA protection:
· EU: UVA circle logo
· UK (Boots): 5 stars (relative to SPF)
· Japan & Korea: PA++++
· Australia & US: Broad Spectrum
Sunscreen use-by dates matter, as efficacy can decline after expiry. Storage away from heat, such as in hot cars, should also be avoided.
Skin/eye sensitivity
If you have eczema-prone, reactive or highly sensitive skin, mineral sunscreen with zinc oxide and titanium dioxide is your best choice as you're less likely to react. True sunscreen allergy is rare, but irritation and sensitivity reactions are relatively common. Scientific sources behind patch testing for sunscreen allergens show chemical filters, especially the older ones such as oxybenzone (benzophenone-3) and octinoxate (ethylhexyl methoxycinnamate) may be problematic for some people. Get to know your triggers and keep a list of anything you wish to avoid. The only way to be absolutely sure of ingredients is to study the INCI list on the product packaging.
If I’m interested in a sunscreen, I also look for trusted reviews from real customers (not incentivised with free products). I always read the one star reviews as well as the 5 stars.
Texture & feel on the skin
Choose from a basic sunscreen that does the job, or a sophisticated formula that has a multitude of other skin benefits also. If you find something that works well for you, stick to it.
Ethics about environmental protection
Increasingly we hear that certain sunscreen ingredients are potentially harmful to the environment. Some places such as Hawaii have banned chemical sun filters oxybenzone and octinoxate to protect coral reefs. There's plenty to read online if you're interested and you can find sunscreens that are 'marine-safe' although it's not a regulated term. Look up the "HEL" list to find all the ingredients to avoid.
Ethics about animal testing
If we care about animal testing, we can’t always rely on brand owners to be transparent. Sunscreens sold in China are often classified as “special-use cosmetics” which may require animal testing, depending on how and where they are registered.
As well as reading brand statements I like to check independent databases to discover whether brands or their parent companies support animal testing. Look at Leaping Bunny, Peta and Cruelty-free Kitty for reliable information.
Health concerns
Another complex subject worth being aware of is whether certain ingredients may have wider implications for health. For example, the EU and UK has moved to ban 4-MBC (4-Methylbenzylidene camphor, or enzacamene), an organic UVB filter compound, due to endocrine-disrupting potential and insufficient safety data regarding genotoxicity. Certain ingredients continue to be under review, such as octocrylene.
Brand Reputation
Recently there have been some reports of sunscreens not performing as indicated. In 2025 Which? reported that a sunscreen by Morrisons and one by Ultrasun didn’t stand up to independent testing and provided less protection than claimed. Another example - in Australia in 2025 an independent report found that 16 out of 20 sunscreens didn’t give the level of protection stated, including products by Bondi Sands and Ultra Violette. Some brands disputed the testing (including Ultrasun), others withdrew products.
I’ve used Ultrasun for some years and never found it lacking, so will be watching with interest whether these reports brings any more scrutiny.
Cost
You can pay £5 or £50 for your sunscreen, so it all depends on your budget and your criteria.
In the UK sunscreen is still classed as a cosmetic, so we pay tax on these products. There are campaigns being run by charities and other organisations to remove this tax, but in the meantime you can often find retailers offering 20% off sunscreen as a matter of principle, or as a promotion.
How To Apply
Sunscreen needs an even, uninterrupted layer to work properly. Clean your skin & moisturise first, then apply your sunscreen once your moisturiser has absorbed. If you wish to wear foundation or tinted moisturiser on top of your sunscreen, you can apply this very lightly once the sunscreen has ‘set’. Never mix your sunscreen with other products as this reduces its effectiveness. Reapply sunscreen every 2 hours and after swimming, sweating or rubbing, so that it protects you throughout the day.
References
If you’d like a list of references for this blog, do get in touch.
Thank you for reading & stay safe in the sun.
Lucy, April 2026