StyleWatch25 Star-Tested Beauty Tips & Tricks

IT'S A WASH!

Wondering how often is too often to shampoo? "It all depends on your scalp," says Dr. Heidi A. Waldorf, director of laser and cosmetic dermatology at New York's Mount Sinai Medical Center. "If it's oily, or if you have dandruff or other issues, washing daily may be helpful. You also may want to shampoo more in summer. Otherwise, you can probably get away with as little as once a week." To keep hair looking fresh between washes, stars like Blake Lively use Oscar Blandi's Pronto dry shampoo, which absorbs oil without over-drying and adds sexy volume.