Sunblocks protect the skin against sunburns and longer-term damage. Recent advancements in sunblock formulations have resulted in even stronger products that protect against a broader range of ultraviolet light.
Other names: Sunscreen, SPF, sun cream, suntan lotion
How it works: The structure of sunblock's active molecules allows them to absorb light at high energy and release it again at a lower energy state reducing the amount of high-energy light that the skin is exposed to. This is similar to the action of melanin, the body's internally produced sun block, which converts UV radiation into heat. (This is also why people with more melanin in their skin are less like to suffer sunburn.)
Buy: At a pharmacy-or almost anywhere else. $5 to $15 for a 3 oz bottle.
New developments: Most of the new developments in sunblock formulation have to do with broadening the light spectrum that the products defend against to include UVA radiation. UVA was once thought to be less dangerous than UVB radiation because you can't see the effects it has on your skin. Because UVA radiation doesn't cause sunburn, it wasn't a cause for concern until recent studies suggested that it can be just as dangerous as UVB radiation.