Ketoconazole shampoo is a medicated antifungal treatment primarily used to combat dandruff, seborrheic dermatitis, and pityriasis versicolor by targeting fungal overgrowth like Malassezia on the scalp. It effectively reduces flaking, itching, and irritation while promoting a cleaner, healthier scalp with consistent application. Available in 1% over-the-counter and 2% prescription strengths.