Dry shampoo is a hair product that is used to absorb dirt, oil, and grease from the scalp without washing it with water. It is usually applied to the top of the head and other areas of hair that are visibly greasy. Dry shampoo is a cosmetic product that is applied to dry hair, unlike traditional wet shampoos and conditioners. It is used to freshen hair after working out, a humid commute, or to extend the life of a blowout. It can also be useful for people with disabilities who have a hard time taking showers without assistance. Dry shampoo is made with a base of alcohol or starch, and when sprayed into the hair, the alcohol or starch soaks up oil and grease, making it look cleaner. Dry shampoo is not a full-time substitute for washing hair with water, but rather a hair freshener that does nothing to clean the scalp, which collects dirt. Experts recommend using dry shampoo no more than two days in a row and for no more than three months at a time to avoid scalp and hair damage. There are many types of dry shampoo available in the market, including powder form or aerosol spray, and some are made specifically for different hair colors and types.