Dr. Allies Dandruff Control Shampoo Key Ingredients: Salicylic Acid, Biotin, Aloe Vera, Tea Tree Oil. Description: NEW/UNUSED. Dr. Allies Professionals Dandruff Control Shampoo (250ml). Advanced Scalp Repair Formula guaranteed to reduce dandruff up to 100%. Contains Salicylic Acid for exfoliation, Biotin for strength, and Tea Tree Oil for its antifungal properties. Suitable for All Hair Types.