Hello, Welcome to healthcare magic, Dandruff is caused by a fungus called Malassezia. This fungus is a normal commensal (resident in the body). Some people will mount an allergy against it causing dandruff. This fungus lives in oily skin. Use a shampoo containing Ketoconazole 2% and ZPTO 1% thrice a week for a month. (Eg: Scalpe ) After that continue using at least once a week for maintaining the improvement. Do not apply oil on your scalp. If you have tried this treatment earlier and still it has not come down you need to take a dermatologist s consultation. A reassessment of diagnosis is required to rule out seborrhoeic dermatitis and scalp psoriasis as both of them can present with resistant scaling over scalp which resembles dandruff. The treatment in these cases will be slightly different. Hope this helped Take care.