Dandruff can sabotage even the most fabulous hairstyle. And to make matters worse, identifying the source of those pesky flakes can be a challenge. While some cases are caused by excessive sweating or stress, others can be attributed to food allergies or simple genetics. But whatever the underlying reason, there's no doubt that dry, wintry weather can exacerbate the issue. For this reason, Kiehl's recently introduced the Herbal Shampoo & Scalp Treatment for Dandruff Control ($17.50, kiehls.com)--a gentle, soothing formula that combats itching, redness, and irritation. Packed with aloe leaf juice and eucalyptus extract, the treatment lathers up like a champ, leaves the scalp feeling refreshed, and smells deliciously minty. Plus, it renders all hair types soft, shiny, and manageable. Best of all, the addition of pyrithione zinc prevents the reoccurrence of symptoms, providing further insurance against troublesome flakes. --Jamie Stone