Does once-a-day sunscreen work? Relying on it may leave you dangerously exposed

sonos sonos One (Gen 2) - Voice Controlled Smart Speaker with Amazon Alexa Built-in - Black read more

Protection: Journalist Jennie Agg road-tested four products which claim 8-hour protection

Protection: Journalist Jennie Agg road-tested four products which claim 8-hour protection

Can you really trust a ‘once-a-day’ sunscreen? With claims on the bottle such as ‘up to 8 hours’ sun protection’ they’re tempting when you’ve planned a long day at the beach.

But for how long do these products really protect your skin? Nowhere near as long as you might hope, as I discovered when I put four leading brands to the test.

As these pictures show, you probably shouldn’t take a ‘once-a-day’ sunscreen at face value. The images were made by L’Atelier Aesthetics, a Harley Street skin clinic, with a scanner that’s normally used to show sun damage but also shows where sunscreen is on your skin.

This is because both melanin, the dark pigment in skin produced by sun exposure, and sunscreen absorb UV light. In these pictures, the darker areas are where the sunscreen has been applied. Paler areas show where there’s little or no sunscreen.

Each morning at 9am for four days, I applied one of the products that claimed to offer all-day protection, had my face scanned then went about my day as normal. I didn’t apply make-up, exercise or get my face wet. All the sunscreens had to contend with was me eating, drinking and blowing my nose.

After eight hours, I returned for an ‘after’ picture. By the end of the day none of the products offered anything like the level of protection they had in the morning.

‘These pictures are worrying,’ says Dr Justine Hextall, a consultant dermatologist at the Tarrant Street Clinic in West Sussex and a member of the British Association of Dermatologists skin cancer sub-committee.

‘The assumption with a “once-a-day” product is that you’ll have the same protection at 5pm as you had at 9am and won’t need to re-apply it. But clearly this isn’t the case.’

'By the end of the day none of the products offered anything like the level of protection they had in the morning,' said Ms Agg as she detailed the analysis of each product

'By the end of the day none of the products offered anything like the level of protection they had in the morning,' said Ms Agg as she detailed the analysis of each product

If a product’s protection doesn’t last as long as you think you run the risk of sunburn. Getting sunburnt just once every two years can triple your risk of melanoma — the most dangerous type of skin cancer, according to Cancer Research UK.

‘The default for many people when they’re on holiday is to stick sunscreen on in the morning and not re-apply it, especially if they use a high factor as they think it will last longer,’ says Dr Hextall.

‘“Once-a-day” labels just add to this myth. People forget that we physically remove sunscreens as we swim, sweat or touch our face — and factor 50 comes off just as easily as a factor 15.’

A sunscreen can be made to be longer-lasting by adding ingredients that help the product ‘grip’ the skin more, or by using chemical UV filters said to be more stable meaning they will be ‘used up’ more slowly, explains Dr Hextall.

In Australia brands are no longer allowed to describe sunscreen as ‘once a day’. In the UK, there’s no such rule — but the UK’s Cosmetic, Toiletry and Perfumery Association (CTPA) says that the industry is trying to move toward using the term ‘durable sunscreen’. ‘All sun protection products, including durable sunscreens, must adhere to strict legislation that not only requires them to be safe, but they have to deliver the protection claimed on the pack,’ says Emma Meredith, a pharmacist and director-general of the CTPA.

But if a product is going to use the term once a day ‘they have to be able to prove that the protection achieved at the end of the day is the same as it was at the start of the day’, insists Dr Hextall.

Here’s how the products performed . . .

SOLTAN ONCE 8 HOUR PROTECT SPRAY SPF30

Worth it? Soltan Once 8-Hour Sprat 30SPF

Worth it? Soltan Once 8-Hour Sprat 30SPF

200ml, £10, boots.com

CLAIM: ‘Up to 8hr sun protection’

9AM: Out of the four products I tested, this felt the nicest to apply. It absorbed quickly and, as you can see, I easily achieved an even coating — only missing a few small spots around my eyes and under my nose, leaving them exposed to UV rays (these are common areas to miss, according to consultant dermatologist Dr Justine Hextall — and are also vulnerable to skin cancers).

It felt heavy but absorbed quickly and gave a nice subtle sheen. It is more expensive than a standard Soltan sunscreen with the same SPF — at £10 compared to £4.50 for the same volume of Soltan Protect & Moisturise SPF30.

‘Like all of the products tested here, this contains the chemical UV filters octocrylene and avobenzone,’ says Dr Hextall. ‘Octocrylene is quite an oily ingredient and tends to enable a better coating of UV filters on the skin that tend to stay put for longer.’

EIGHT HOURS LATER

Soltan Once was applied successfully in the morning, with full coverage across the face

By the evening, most of the protection around the nose, mouth and cheeks is gone

Consumer test: Soltan Once went on OK, but most of the protection around the nose, mouth and cheeks had gone within eight hours

 As you can see from my white speckled face, most of the protection around my nose and mouth and across my cheeks has gone. 

While some sunscreen appears to have stayed on the sides of my face and my forehead is pretty well coated, the coverage is not as even as it was, with pale patches around my jawline, possibly where I’ve touched my face.

Interestingly, even now my skin still felt quite sticky. ‘Some sunscreen ingredients, such as octocrylene, have a moisturising effect, so this might be why your face felt oily all day,’ explains Dr Hextall.

‘But it may be that the skin barrier is more hydrated after using the product so it might give you a false sense of how much is on your face.’

RIEMANN P20 ONCE A DAY SUN PROTECTION SPF20

Reimann P20: 'This has a very runny, oily consistency. It also has a harsh smell'

Reimann P20: 'This has a very runny, oily consistency. It also has a harsh smell'

200ml, from £14, most chemists

CLAIM: ‘10 hours’ sun protection’

9AM: This has a very runny, oily consistency and I found it harder to know where I’d applied it than the Soltan. It also has a harsh, astringent

read more from dailymail.....

Get the latest news delivered to your inbox

Follow us on social media networks

NEXT Poor people are 42% less likely to suffer from depression or anxiety if they ...