You regularly see flakes in your hair. Or it’s snowing outside.
Shampoo Rx: Selsun Blue ($7 @ Amazon.com)
A lot of companies have come out with different Rx’s for flakes over the years, but the Selsun Blue guys are still the pros at fixes your itchy, dry scalp. It has salicylic acid, which basically dissolves the top layer of skin on your scalp — but not in a gross way. In a gradual way that helps your skin look good (not flaky) again.