It depends on the amount of sebum and sweat secretion, temperature, humidity, age, etc., the length of time between washes will vary
based on the person.
Those who have thin/fine hair, exercise, and sweat during the day-or those who live in a very humid place- should be shampooing their hair daily. The average individual can typically go 2 to 3 days without shampooing their hair. However, if your hair is visibly oily or you are experiencing any type of dandruff, it is time to wash.
It is important to keep your scalp clean and moisturized for healthy hair growth.
If you are worried about hair loss, dry and flaky scalp, it is a good idea to switch to shampoo that contains amino acid-based cleansing ingredients.