Are you being sun safe? SPF myths debunked by a dermatologist

Please wear your SPF. Every. Single. Day.

Fact: the best sun cream and best facial sunscreens are essential to reduce your risk of skin cancer and also to prevent visible signs of ageing.

Sadly, there are a lot of SPF myths that over time have been ingrained into us as fact. Sun cream is only for summer, right? Actually, wrong...

For a clear-cut picture, we asked Dr Anjali Mahto, consultant dermatologist and author of The Skincare Bible, to set a few things straight.

Myth 1: You only need to wear sunscreen in summer, or when the sun is out

'Even if you can’t see any blue sky, a significant amount of UV rays can still get through the clouds,' explains Dr Anjali Mahto. 'It’s best to apply sunscreen if you’re out and about.'

Myth 2: Darker skin tones don't need to use SPF

'Those with olive or pigmented skin often think they don’t need sunscreen, but skin of colour is also sensitive to damage caused by UV and requires protection,' the doctor explains.

'Darker skin is relatively more protected from sun damage with a natural SPF of around 13.4, compared to its fairer counterparts which have an average of 3.4. But while this does mean the onset of sun damage (wrinkles, skin laxity and sagging, to name a few) is less common in dark skin, compared to an age equivalent individual of white skin, dark skin types are still vulnerable to sun damage.' Check out our guide to the best sun creams for dark skin tones.

Myth 3: Every sun cream protects against all kinds of damage from the sun

'When choosing a sunscreen look for a high protection SPF (30 or more), to protect against UVB, and the UVA circle logo and/or 4 or 5 UVA stars to protect against UVA,' explains Dr Anjali.

'IR-A appears to induce free radical formation and penetrate the skin, causing damage that can potentially lead to skin ageing. Traditional sun creams do not generally have IR-A protection, we need to seek out products that offer triple protection, that protects against IR-A rays, too.

Myth 4: You only need to apply sunscreen once to be protected all-day

'Despite what the packaging promises, swimming, sweating, rubbing, or towelling down mean you will end up removing the sunscreen from your body,' Dr Anjali says. 'Always reapply after sporting activity, or at least every two hours.'

Myth 5: The SPF scale is linear

There is a massive difference between no SPF and the protection offered by an SPF of as little as 15. 'SPF 30 does not offer twice the protection as SPF 15, even though it offers a higher level of protection, so don’t be fooled,' says Dr Anjali. 'Similarly, factor 20 is not twice as good as factor 10 – an SPF 15 blocks about 93 per cent of UVB rays, while an SPF 30 blocks 97 per cent and SPF 50 blocks 98 per cent. No sunscreen offers 100 per cent protection.'

Lucy is a freelance beauty editor and contributor at Marie Claire, and has also written for titles including Cosmopolitan, Refinery29, Glamour and woman&home. She was previously Marie Claire’s junior beauty editor. During her career, she’s covered everything from backstage beauty at fashion week to interviews with famous faces like Drag Race royalty and Little Mix. As for her beauty ethos, she’s a big advocate for not having to spend a fortune on beauty products to get good results. When she’s not got beauty on the brain you’ll probably find her reading or Netflix-ing.