Using too much Shampoo
Q: Are there any disadvantages in applying too much shampoo in your hair? Will the use of too much shampoo damage your hair or make it dry out or something?A: Well, aside from being a phenomenal waste of money, the over-application of most shampoos won't have too detrimental an effect to the hair. The lathering process will be inhibited by too much shampoo, since it needs a good balance of shampoo to water.
However, when you use harsher shampoos (such as clarifying shampoos and volumizing shampoos) you can create problems by shampooing too often. Clarifying shampoos especially are designed to strip away oils and residue from the hair and can completely strip the hair of its natural oils and emollients.
©Hairfinder.com
See also:
How to wash your hair and use the right amount of shampoo
Can washing your hair every day dry it out?
Use soap to wash your hair
Wash your hair with conditioner only