Shampoo primarily cleans the scalp and hair, so selection should begin with how your scalp behaves, while also considering the condition of your hair lengths.
How to Choose the Right Shampoo for Your Hair and Scalp
Notice whether your scalp becomes oily quickly, feels dry or tight, or accumulates styling products.
Your scalp and hair lengths can also have different needs. An oily scalp may coexist with dry or damaged ends.
There is no universal washing frequency. Climate, activity, scalp behaviour and product use can all affect how often cleansing feels appropriate.
Persistent dandruff, significant itching, inflammation, pain or unusual hair loss should not automatically be treated as ordinary cosmetic concerns. Seek appropriately qualified professional assessment when symptoms are persistent or concerning.
The practical principle is simple: choose for the scalp first, while respecting the condition of the hair itself.