What’s the best SPF for you?

Craving a radiant summer glow? There’s a fine line between looking sun-kissed and sun-singed. The answer? SPF. But you knew that. SPF is non-negotiable in any routine (come rain or shine). You can spend £££ on skincare, but it won’t make a real difference if you don’t use an effective SPF, daily.

Basking in the sun may offer a host of health benefits (studies show that natural sunlight can boost serotonin levels, lower blood pressure and strengthen bones), but there is no such thing as a ‘safe’ tan. ‘The safest way to get a tan is slowly and through a sunscreen,’ says consultant dermatologist Dr Nick Lowe. ‘You’ll still have some sun damage – that’s what a tan is – but you will have less burn.’

And yet even beauty pros can be left befuddled by the array of factors, acronyms and even stars attributed to sunscreens, let alone when to use SPF, how much to use and how often. In strolls this handy guide…

Both UVA and UVB rays do harm to the skin but the effects they have are a little different, so it’s important that you’re protected against both (hence ‘broad-spectrum’ sunscreen). Think of UVA as the ‘ageing’ rays and UVB as the ‘burning’ ones. 'UVA are the deepest-penetrating and most ageing ultraviolet rays,’ says Dr Lowe. UVB rays aren’t able to penetrate the skin as deeply, thanks to their shorter wavelengths, but they cause more damage to the surface and are the cause of most skin cancers.

The sun protection factor (SPF) is the measure of how long a sunscreen will protect you from UVB (and only UVB) rays compared to if you weren’t wearing any. However, a sunscreen with an SPF of 30 is not twice as effective as one with an SPF of 15. In fact, SPF15 filters about 93% of UVB rays, SPF30 filters 97% and SPF50 filters 98%. Layering all of these factors on top of each other will also never give you 100% coverage.

No. All skin tones burn and all need a broad-spectrum, high-SPF sunscreen. Rates of melanoma among those with darker skin tones are just as high as those among people with lighter skin tones.

Physical sunscreens (or UV reflectors) block the sun’s rays on the surface of the skin, while chemical sunscreens (or UV absorbers) absorb into the skin, where they convert the sun’s rays into heat and release them. Dr Lowe warns against getting too bogged down in the word ‘chemical’. ‘There’s a lot of hocus pocus about chemical vs physical sunscreens as all sunscreens are made up of chemicals,’ he says. ‘Even so-called “chemical-free” or physical sunscreens are made up of titanium dioxides and zinc oxides which are, of course, chemicals. In general, chemical sunscreens tend to be best for tanning, while sensitive skin and rosacea sufferers often benefit from physical sunscreens as they deflect heat from the sun’s energy away from the skin.’

For the face: SPF is the final layer in your skincare routine; apply two fingers’ worth (enough for face, neck, décolleté and hands) and wait 60 seconds for it to fix, pre-makeup. 

For the body: you’ll need about one teaspoon of SPF for your arms, two for your legs and two for your torso (front and back). 

Apply 30 minutes before sun exposure, reapplying every two hours.

Did you know that sand and sea foam reflect UV rays, making them more potent? Do try limiting exposure to the sun between 11am and 4pm and adding in some antioxidant insurance in the form of a vitamin C serum, which can be layered under your SPF to help neutralise damaging UV rays. And the most important sunscreen rule? Reapply, reapply, reapply! Every two hours and immediately after swimming.