Skin is our body’s largest organ – on average, an adult has about two square metres of it, or in weight about 3.6 kilograms. It protects our internal organs, produces vitamins and minerals, provides tactile feedback and helps us retain water… that’s why keeping it moisturised and well protected is so important. Since it’s so hard-working and subject to so much, however, skin constantly needs to reproduce itself. For each minute that goes by, you’ve shed 40,000 skin cells, and your skin is entirely renewed every 35 or so days. If you live for 80 years, you’ll have renewed your skin approximately 800 times, shedding up to 2,880 kilograms.