My skincare regimen is extensive to put it lightly. I regularly slather miracle serums and potions on my face (and neck!) with wild abandon. But this summer, I've finally given in to some streamlining. And now there's one secret ingredient that I won't leave the house without, and what it is just might surprise you. It's not a $500 oil phenom but good old zinc oxide. Every dermatologist I've ever interviewed (and there have been many) has insisted that mineral-based sunscreens such as zinc are the only real way to prevent skin damage and premature aging. Dr. Cybele Fishman told us that it's an inert mineral which blocks both UVA and UVB rays. Zinc oxide and titanium dioxide sit on top of the skin, forming a barrier against the sun's rays. Sunscreens with zinc start protecting you as soon as you put them on. You may have heard you should look for a "broad-spectrum" product that protects against both UVA and UVB rays. Any sunscreen that contains the physical blocker zinc oxide or titanium dioxide will have you covered. This year I turned 40 and my charming freckles that I hadn't seen since childhood reemerged as sunspots—significantly less charming. Dr. David Colbert told me the damage wasn't new or recently acquired. It was from all the days at the beach that I laid around with nothing but a reflector and a bottle of baby oil coming back to haunt me. Colbert said the only way to truly prevent them from coming back is with zinc sunscreens. Even wearing an SPF 50 UVA doesn't have the same protection as a mineral sunscreen. If zinc brings to mind the white, pasty noses of '80s lifeguards, let me introduce you to the new wave. Click through the gallery to see the best, most lightweight and effective products out there. Happy Summer!