From argan to coconut, natural oils are totally having a moment. So which trendy, all-powerful oil is right for your skin type? We spoke with Dr. Joshua Zeichner, director of cosmetic and clinical research in the Department of Dermatology at Mount Sinai Medical Center, to come up with this handy-dandy guide. Here's a bit more info about the natural oils in each category, from Dr. Zeichner: On anti-aging: "Oils used to prevent skin aging are rich in fatty acids and antioxidants. Omega-3 fatty acids are used by skin cells to make healthy membranes, reduce inflammation, and promote healthy collagen. Antioxidants such as vitamin E prevent free-radical damage from UV light exposure and help maintain healthy collagen and elastin." On adding moisture: "Healthy fats are not only good to eat but also to help hydrate your skin. When applied to dry skin, oils such as olive oil can soothe without causing irritation or allergies. Avocado oil is rich in vitamins, fatty acids, and antioxidants, especially vitamin E. It can help repair the skin barrier and act as a natural skin emollient. Avocados have high levels of sterols, which are natural fats in plants, which can soothe irritated skin. While coconut and