What’s the secret of lasting, natural beauty? The capacity of the skin and hair to protect themselves and stay healthy. The skin is the largest organ in our body. It protects us from environmental factors and promotes immune response and metabolic processes. It’s our largest sensory organ, too. However, it also acts as the interface through which we come into contact with the world. The same goes for our hair: it protects our scalp from UV rays, for instance, has a heat-regulating effect, and, last but not least, plays a big role in our appearance.