While sunscreen can prevent you from becoming darker, it will not whiten your skin.
More Info: You should use sunscreen each and every day to protect your skin and prevent aging. Sun damage is cumulative and adds up over time. Even a few bad sunburns as a child can lead to skin cancer years later. There is also evidence that sun damage is the primary cause of wrinkles and age spots. Although cosmetic issues are not life threatening, they do cause a lot of concern and stress for many people as the years go by. To be kind to your skin, apply sunscreen about 30 to 40 minutes before you go outside and remember to reapply often for the best results.
Have you ever wondered what kind of sunscreen you should buy or what those numbers actually mean? Sunscreen comes in various lotions, creams, and gels formulas. It can be contained in bottles, squeeze containers, pumps, and spay-on applicators. Pick whatever works best for you and feels good on your skin. After all, if something feels too heavy or greasy or it's too hard to apply, you probably won't use it too often. Make sure you buy a product that protects from both UV-A rays and UV-B rays. The SPF, or Sun Protection Factor, is also important. The higher the number, the more protection you have from the burning UV-B rays. The number indicates how much longer you have to stay out in the sun before you burn than if you were unprotected. For example, if you usually burn in 10 minutes without sunscreen, a SPF 15 would give you 150 minutes and SPF 30 would give you 300 minutes.