If your skin has suddenly turned tight, flaky or unusually sensitive, it may be your skin barrier trying to tell you something. Your skin barrier, a.k.a. the outermost layer of skin, plays a crucial role in keeping moisture in and irritants out. Over-exfoliating, stress, cold weather and too many actives (like retinol) can all weaken this protective layer, leading to irritation and moisture loss. The good news is that there's a way to fix it: barrier-supporting formulas, which help replenish what skin needs to stay calm, resilient and glowing.