The skin is a fascinating organ – it’s the largest one we have and the only one visible to others. It has to hold the rest of our organs in, maintain our precise body temperature, keep out toxins and radiation, and manufacture vitamins. We use it to feel the world and each other.

Skin Deep explores why the skin is so important for our health, including surprising new research on how wrinkles can drive ageing, how skin wounds can impact gut health and how Botox can change the brain. It asks: can we really stop our skin from aging using creams and supplements? Is there such a thing as a healthy tan? And does washing with soap actually make us smell worse? Blending the latest research with expert interviews, Alice Klein spends a day in a Botox clinic, meets people born without collagen whose lives have been transformed by a radical new gene therapy, and visits a lab in japan making robot faces out of living skin to provide a deep understanding of our largest organ.