Chemical warfare
Credit: Dana Hoff / Getty Images

The best way to knock it out is with the right lab-tested chemicals. "There are a few herbal products on the market, and some people tout the use of tea tree oil," says Krant. "But these are not as effective as the use of the very safe over the counter shampoos containing zinc pyrithione, selenium sulfide, and ketoconazole." These chemical compounds possess antimicrobial, antifungal, anti-proliferative and anti-inflammatory properties, meaning they'll wipe Malassezia out, keep it from coming back, and help heal your scalp.