Sunscreens protect the skin by using two main types of active ingredients: physical blockers and chemical absorbers. Both types work to prevent UV radiation from damaging the skin. Choose a sunscreen with an SPF of 30 or higher. SPF measures the level of protection against UVB rays, with higher numbers offering more protection. Sunscreens come in various forms, including lotions, sprays, and powders. Select a formulation that suits your preferences and is easy for you to apply evenly.