Dr. Neera Nathan on Instagram: "Stringy, front pieces or greasy roots? I’m a dermatologist and here is a wash day routine for oily hair that will help keep your hair looking fresh for longer between washes. 1. Use a salicylic acid shampoo. We know that some of the best products come in the least sexy packages - Neutrogena T/SAL shampoo is no exception. It contains 3% salicylic acid which is a great active to reduce sebum (oil production), remove build up and exfoliate the scalp. Use this shampoo