Olive oil has been revered for centuries as a natural moisturizer, and with good reason. “Olive oil is ultra-hydrating,” says Dr. Longwill. It creates a barrier that protects dry skin and is particularly helpful for people who have psoriasis or eczema. Use it straight from the bottle — yes, the same olive oil you use to make healthy salad dressings — to slather on after a shower. Or try it as a homemade hair treatment for split ends. “Hair follicles absorb olive oil nicely,” says Longwill. You can find olive oil in numerous skin and hair care products, including soaps, facial washes, moisturizers, shampoos, and conditioners.