Pick prebiotics

Shampoo is meant to cleanse hair, but harsh detergents can strip good bacteria from the scalp, causing irritation that can make hair thin and brittle, says New York City dermatologist Julie Russak, M.D. But a scalp treatment made with prebiotics can help. When applied to the scalp before shampooing, these compounds “feed” good bacteria, balancing skin on the scalp so hair can get clean without compromising healthy hair growth. One to try: CurlSmith Super Slip Pre-Biotic Primer (Ulta.com)