Scorching flat irons and high-lift bleach take the blame, but substantial damage can happen to a strand of hair before it’s even visible. Each baby hair incubates in its follicle—four millimeters below the surface of the scalp—for about 14 days. During this two-week period, any oxidative stress will compromise the future strength of each hair and make it significantly weaker from the get-go. “Our scalp’s health is reflected in the condition and appearance of our hair,” adds Melville, NY dermatologist Kally Papantoniou, MD.
The number-one cause of scalp stress? Malassezia globosa—the same fungus that also causes dandruff, and which Dr. Rolanda Wilkerson, PhD, principal scientist at Procter & Gamble, says exists on every single scalp. Flakes and itchiness are a clear sign that Malassezia is wreaking havoc, but even if a scalp seems calm on the surface, there may still be trouble brewing underneath. Here, 12 potent picks to keep your scalp in tip-top condition.