LED technology has been used to address a number of skin issues, such as eczema, mild to moderate acne and psoriasis in a medical setting. But now you can buy your own LED mask or device for use at home. Adverts are everywhere on social media, with lots of influencers promoting them. Mask developers make big claims that at-home LED masks can be used to treat acne scars, sun damage and fine lines - but what does the evidence show?

BBC journalist Imogen James explains the trend and takes us through how and if these at-home LED masks work. Rio Rennalls from the What in the World team tells us why he uses one.

Some dermatologists and experts have raised concerns about the efficacy of these masks. David Robert Grimes, a scientist and author in Ireland, gives us his views on the technology. And we hear from dermatologist Dr. Montserrat Fernández-Guarino.

Instagram: @bbcwhatintheworld