There are a number of limitations to dry shampoo, the biggest being that it doesn't clean your hair as thoroughly as traditional, or "wet" shampoo does. Wet shampoo also promotes a healthy scalp by removing product buildup, dead skin cells, and dandruff. "Your hair and scalp needs to be washed and rinsed intermittently to keep it clean," dermatologist Wilma Bergfeld told the Cleveland Clinic. "The scalp collects chemicals and pollutants both from the air and from cosmetic care products, and if you only use a dry shampoo, the cleansing is only minimal but it does freshen the hair by removing oils."
Another limitation is that if you continue to use dry shampoo with no washes in-between, the product eventually builds up on your scalp, making it counterproductive toward the initial goal of cleansing your hair. At the most, the Cleveland Clinic suggests you can use a dry shampoo product sparsely for up to three months. "Sparsely" is the key word here, as using dry shampoo two or more days in a row can result in irritation or dryness, per Healthline. Though there are mixed opinions on this, some people also say that you should avoid using heat styling tools after applying dry shampoo as it might further dry your hair out, resulting in damage.
