Premature Greying of hair can be accounted to a number of causes, frequently a cause can not be pinpointed. There is little that can be done to reverse graying. Many serums and solutions are available namely Altris, Qsera black, to name a few. Additionally hair nutrient supplements containing calcium pantothenate have also been shown to work. All these treatments have highly variable results hence how much effective it will be in your case can not be predicted. You can consult your dermatologist to know what will work best for you. Regards, Dr.Shruti Jadhav Devershi, Sólskin Professional Dermacare, Kharadi, Pune.