Hello, Welcome to healthcare magic, Dandruff is caused by a fungus called Malazessia. This fungus is a normal commensal( residing 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. After that continue using once a week at least for maintaining the improvement. Do not apply oil on your scalp. Premature Greying is still a poorly understood entity. The causes suggested are genetic, Vitamin deficiencies, Stress etc. Dandruff is not one among the causes hypothesised. The treatment recommended is vitamin supplements with atleast 100 to 200 mg of calcium pantothenate. Even Biotin and anti oxidants help. Now a new product has come in the market(Melitane) which has peptide which stimulates the pigment producing cells of hair. Sufficient studies and experience is not yet available for it. You can treat both simultaneously. Dandruff treatment is long term for years. You just need to maintain shampoo use once a week. Grey hair treatment also will last for many months till you get improvement. Hope this helped Take care