As we age, the proteins, lipids, and molecules that make up our skin barrier and structure decline. Our bodies naturally produce their own supply of collagen, ceramides, hyaluronic acid, squalene (etc.) throughout our lifetimes. But the rate of this production slowly reduces until the body can no longer make enough to restore the natural levels, and they begin to taper off. And thus, we see the results: increased dryness and loss of firmness.
