Choice of shampoo would depend on hair and scalp type, an individual liking, work profile, weather and environment too. Person with dry frizzy hair can use a mild shampoo and a heavy protein conditioner. Person who moves a lot outdoors may require to shampoo hair more frequently, may use shampoo conditioner combination. Person with excessively oily scalp and haor may require only shampoo The base ingredients for most shampoos are same with a subtle difference in extra additives like colour, fragrance, foaming agents etc. You can always try the smaller version first. But you may have to change the shampoo conditioner according to season and weather. Avoid changing products every other day But definitely change it promptly, if it is damaging your hair. Dr. Jolly Shah DNB Skin