What is collagen?
Collagen is the most important protein in the body, present in bones, skin and other connective tissues. In addition to the production of keratine, collagen is responsible for skin's elasticity and firmness. However, collagen fibers get worn over time just like the springs of a mattress.
But the comparison ends there: our skin produces a little more collagen every day. Unfortunately, with age, the new collagen is less well 'organized'. Dehydration and badly structured collagen leads to less firm, less plump skin. Like a sinking mattress, it starts to sag.