From the mid-twenties, the first signs of skin ageing begin to appear. As we age, the process of cell renewal slows down, which weakens the fibroblasts and therefore the structure of the skin. Indeed, collagen, hyaluronic acid, and elastin, which allow the skin to remain firm, smooth, and elastic, gradually see their levels decrease. This results from a combination of internal and external ageing factors. Wrinkles, fine lines, and skin sagging are the most obvious manifestations of skin ageing and tend to become more pronounced with age.