The most effective shampoos for Tinea Versicolor are ketoconazole (e.g., Nizoral) and selenium sulfide (e.g., Selsun), along with zinc pyrithione-based washes, as they help control the overgrowth of Malassezia yeast that causes the infection. Ketoconazole works by directly stopping fungal growth, while selenium sulfide reduces yeast production on the skin and helps remove excess scaling, both allowing the skin to gradually return to normal. These shampoos should be applied to affected skin (not just the scalp), left on for 5–10 minutes before rinsing, usually once daily for 1–2 weeks; in recurrent cases, they may be used weekly or monthly as maintenance to prevent flare-ups. If the condition keeps returning, spreads widely, or does not improve after a few weeks of proper OTC treatment, you should see a dermatologist, as prescription-strength antifungal creams or oral medications may be needed for better control.