The real reason why this is the best-selling SPF right now Created in the world’s toughest place to get sunscreen approved, this cult SPF is creating a buzz in the UK - here's why 25 May 2021 • 5:25pm Ask any expert about the essentials of skincare and you'll be hard pressed to find someone who doesn't rank SPF in the top spot. It's a wonder then that so many of us still struggle with it - some are too thick, some leave a grey cast and others aren't very good for the environment. Even Gwyneth Paltrow recently admitted that when it comes to sunscreen, she is not 'a head to toe slatherer', to the shock of many dermatologists.