MYTH: SPF only matters on the face.
REALITY: If you don't protect your neck now with SPF, prepare to be covering up in your 50s. The same age-fighting ingredients you put on your face can also be applied below the chin, but be careful with retinol and acids. "The skin on the neck is more sensitive," says Dr. Brandt, who advises you use retinol on this fragile area no more than two or three times a week. We like
Clinique's Youth Surge SPF 15 ($50;
clinique.com), which turns back the time by boosting collagen while protecting from sun damage.