Now that the warmer weather has come (at least for the moment!), people are reaching for the sunscreen. It seems wasteful, but you should not that sunscreen that you have left over from last year. It may not be strong enough. Of course, if you are following these guidelines, you probably won’t have any leftovers:  “You should use up a whole 8 ounce bottle every weekend when applying it to your whole body,” explains Dr. Neal Schultz, a New York City based dermatologist and founder of DermTv.com and creator of BeautyRx. Not using enough can diminish its effects. Plus you should technically be using sunscreen all year long. Check out more tips HERE