White cast, nostalgic smell, never quite rubbed in enough. Yep, that’s sunscreen. It can be the stuff of nightmares when sand is involved. But recently, some TikTok influencers - and even celebrities - are telling their followers that it’s dangerous. They allege that chemicals seep into your skin, and cause harm, even cancer.

But science says no. In this episode, biomedical scientist Judey Pretorius explains how UV rays cause cancer, and that you need chemicals, good ones, to help save your skin from sun damage. She goes through what actually happens when you use sun cream and the benefits.

And what about for darker skin tones? Dr Shadi Kourosh, professor of dermatology at Harvard Medical School, and expert in multi-ethnic skin, tells us how sunscreen is still important even if you have darker skin.

So where did this trend come from - if it’s a myth? BBC disinformation reporter Jacqui Wakefield speaks about reports, famous people and even trad wives. Instagram: @bbcwhatintheworld WhatsApp: +44 0330 12 33 22 6 Email: whatintheworld@bbc.co.uk Presenter: Alex Rhodes Producer: Imogen James, Benita Barden and Emily Horler Editor: Verity Wilde