Relying on sunscreen to save you from skin cancer

Why is this healthy habit a bust? Because you’re probably applying it incorrectly. According to Francesca Fusco, M.D., spokesperson for the Skin Cancer Foundation, people tend to not use enough sunscreen or use it inconsistently or not early enough in life. They also often aren’t using a sunscreen that’s truly effective. Some of her tips for proper use include: Putting sunscreen on over any medication but under makeup; using the equivalent of a shot glass or two to cover your whole body—even under clothes—and then waiting at least 30 minutes before you go outside; and always using a sunscreen that contains the ingredient mexoryl. That last one is a biggie. Sunscreens without mexoryl—which is, to say, most of them—only protect against UVB wavelengths of light. But UVA waves are dangerous as well—possibly more so, considering that they can damage your skin without causing sunburn, leaving you unaware of your risk.