Watch Horizon Season 44 Episode 3 Online

Professor Lesley Regan is on a mission to fill her bathroom cabinet with cosmetics that actually work. Professor Lesley Regan, one of the UK's most well-respected (and glamorous) medical experts, turns her scientific eye on the world of cosmetics. She's just turned 50, and is out to create an experimentally proven beauty cabinet. Unafraid to examine the wrinkles, age spots and broken veins on her own face, Professor Regan explores just what makes us look old, and if we can slow down the ageing process. The extraordinary world of cosmetic testing is revealed, from the British hair lab which makes New York tap water, to the volunteers sun-bathing for science. Sun damage, cellulite and balding all face Professor Regan's scrutiny as she discovers which cosmetics do - and don't - have the scientific evidence to back up their claims.