Your Top SPF Questions Answered
Your Top SPF Questions Answered

Your Top SPF Questions Answered

In this series, we ask the pros to answer your top beauty questions – and this time, they’re all about SPF. From how much to apply, to the difference between factor 50 and factor 30, we put some of the SL Community’s recent questions to two dermatologists…
By Rebecca Hull

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Let’s Start With SPF50 & SPF30 – Is There Much Difference In Terms Of Protection?

“I can see why this a top question within the SL Community. They don’t differ as much as you may think. SPF30 filters out 97% of UVB rays, whereas factor 50 blocks out around 98%. So, there’s a 1% incremental benefit in terms of protection. That said, SPF works on a time-lapse basis. For instance, if you go out in the sun and it takes you ten minutes to start going red, putting on an SPF30 will mean it takes 30 time longer for that to happen. Similarly, if you apply a factor 50, you have 50 time as long. While they barely differ, I would say SPF50 gives you that extra peace of mind – especially if you’re someone who’s not always on top of reapplication.” Dr. Justine Kluk consultant dermatologist

Speaking Of, How Often You Should Reapply SPF?

“This depends on your activity levels and the amount of UV exposure. For example, on a dark wintery day, application of sunscreen in the morning as part of your routine will suffice. On a bright, sunny day with lots of outdoor activities, I would recommend reapplying sunscreen half an hour before heading out. If you plan to spend the whole day outside, reapplication is recommended every two to three hours. The need for reapplication isn’t because the sunscreen filters stop working – in fact, formulas today are more sophisticated than ever – but because you may miss parts of your skin when you initially apply your SPF. Physical activity, swimming and sweating also play a part – and these situations will give you reason to reapply.” – Dr. Hiva Fassihi, consultant dermatologist for La Roche-Posay

Why Do You Have To Apply SPF 30 Minutes Before Heading Out?

“The 30-minute rule is something SPF brands have always recommended, but recently it’s been challenged by some sunscreen formulators who say SPF protection is immediate from the moment you apply it. However, the British Association of Dermatologists still advises giving it 15-30 minutes post-application before you head out and then topping up again as you sit in the sun. That way you get nice, even protection.” – Dr. Justine

If Your Make-Up Has SPF In, Do You Need Extra Protection?

 “Many of us believe that the sun protection within our make-up is enough to keep sun damage at bay, but it’s not. You would need to apply a teaspoon of your foundation to your face to get enough protection, so it’s best to think of the SPF in your make-up as a ‘booster’ to whatever protection you put on underneath.”– Dr. Hiva

Can You Share Some SPF Recommendations For Children?

“The SunSense Kids Roll On is my favourite. Another tip would be to get your children to put stickers on their SPF bottle – from experience, they normally get engage with the idea of SPF far better if they do this. I also recommend the Calypso Kids Coloured SPF. It comes out blue and then absorbs fast without any traces of colour left behind. I love it for children as they learn how to apply SPF and they can see where it’s gone and where it’s been missed for thorough protection.” – Dr. Justine

How Long Should A Bottle Of Sunscreen Last?

“You need about 30ml of sunscreen to cover your body on sunny holidays, and if you do this about two to three times a day, a standard 250ml bottle should last you for nearly four days. I recommend taking a couple with you to be safe. Remember, most sunscreens have a shelf life of about 12 months, so you shouldn’t always rely on existing ones you have at home. Over time, the texture of SPF can change its efficiency, decreasing the UVR filters’ ability to work. I recommend buying a new bottle every year and chucking out old, unfinished ones.” – Dr. Hiva

If You’re Prone To Heat Rash, Should You Avoid Certain SPF’s?

“It depends on what you mean by ‘heat rash’. This term can suggest different skin conditions. Heat rash can occur in those with sensitive, dry and eczema-prone skin. Other causes of a red and itchy rash in the sun is polymorphic light eruption or ‘prickly’ heat. Either way, it’s important you protect your skin from the damaging effects of UVR – particularly if you’re prone to sensitivities. Use an SPF50 with zero fragrance and minimal ingredients. Those with a higher content of mineral (physical) sunscreen filters – often found in children’s SP’s – are tolerated better by those with sensitivities. Those suffering with prickly heat should stay out of the sun entirely as the condition is triggered by UVA. Try La Roche-Posay’s Anthelios UVMUNE400 SPF50 too – it has excellent, non-irritating coverage and protects against UVA.” – Dr. Hiva

Which SPFs Do You Recommend For Wearing Over Make-Up?

“Normally, your SPF should be applied post-cleanse and before make-up, but if you want to apply one at the end of your routine, look for those that come as a spray. My favourite is Kate Somerville’s SPF Setting Spray. It has a very fine mist, is non-greasy and never disturbs make-up. Another option is the Colorscience Sunforgettable Total Protection Brush. It is a mineral powder that you dust on over your make-up. Garnier’s Ambre Solaire Makeup Super UV Mist is brilliant too.” – Dr. Justine

Similarly, Are There Any Lightweight SPFs You Recommend?

“For the body, the Altruist Invisible Sunpray SPF50 is brilliant. It’s also non-comedogenic, so it’s ideal for those prone to breakouts and acne. You’ll barely feel it on your skin and the formula is totally invisible. For oily-prone skin, I recommend Eucerin’s Oil Control SPF50 and Murad’s Pore Control SPF50. The Ultra Violette Queen Screen SPF50+ Serum is brilliant too, as is the SkinCeuticals Oil Shield UV Defense Sunscreen.” – Dr. Justine

Finally, Is There Such Thing As A ‘Healthy’ Tan? 

“The short answer is no. A tan is what happens when the pigment-producing cells in your skin are exposed to UV rays and they begin to make melanin. The latter acts as an umbrella over the DNA in your cells to protect it from sun damage that could cause cancerous mutations. The fact you’re seeing a tan means your skin is producing more melanin, which means your skin is sensing a threat to its DNA and in turn, trying to create more mini umbrellas.”  – Dr. Justine

Looking for a skin consultation? Book in here with Dr. Hiva & here with Dr. Justine.

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