HAIR CARE ROUTINE FOR GREY HAIR
Shampoo or conditioner is unlikely to help reverse the greying of hair. So there is no point spending extra bucks on them.
Herbal oils with curry leaf, brahmi, bringraj etc. might help to a certain extent. Put them on hair roots overnight.
In addition, correcting the causative factors like nutritional deficiency or hormonal imbalance can help, therefore you should consult a dermatologist.