Everyone knows that an ounce of prevention is better than a pound of cure. That is certainly true for wrinkles and an even worse consequence of too much sun, skin cancer. Protecting your skin from excessive sun exposure is one of the best ways to avoid the long-term deleterious effects of its penetrating radiation rays. While most everyone’s know this, two common mistakes are made with the use of sunscreen that substantially reduces its protective benefits. Applying liberal amounts of sunscreen every few hours is needed for optimal protection, Sunscreen gets rubbed off, is removed by sweating and water and its molecules break down. Most sunscreens do not last beyond two hours. Reapplication is necessary to put back a good protective layer. The sunscreen you use must block both UVA and UVB rays. Sunscreens with SPF only block UVB. Newer broad-spectrum sunscreens block both UVA and UVB rays. As of December 2012, broad-spectrum sunscreens that meet FDA guidelines with SPFs 15 or higher can formally make the claim that the product reduces the risk of skin cancer and early skin aging as well as helps prevent sunburns.