Dry shampoo is a powdered substance that is used to absorb oil in the hair when it is not possible or practical to use water and traditional shampoos. There are a number of commercial products available, and simple recipes can be used to create it at home. Some people choose to use it between regular washings, preventing the need to restyle the hair, in many cases, and avoiding exposing it to excess heat. It is also not unusual for households to keep a small amount of on hand as part of an emergency hygiene kit. In the event that water is not available, the compound can be applied and provide at least a partial cleansing of the hair.
All homemade and commercial dry shampoo products contain some type of powder, which is often worked into the hair in a way similar to the application of wet shampoos. This allows the powder to begin absorbing the excess oil present on the surface of the hair follicles. After leaving the shampoo in place for a short period of time, the residue is brushed or combed out. The end result is that the shampoo removes excess oil and the hair will appear healthy and manageable for several hours.
Since the 1970s, dry shampoo products have been available as powders that are sprinkled into the hair as well as sprays that are sold in aerosol cans. Along with these commercial products, it is possible to make home versions using items such as talcum powder and various herbs and spices. While some of the home versions may leave behind tiny particles that dull the sheen of the hair, there are home recipes that provide a temporary luster to the hair that is very similar to that of using a good quality wet shampoo.
Most hair experts do not recommend using dry products as a permanent substitute for wet shampoos. While it works very well for the occasional application when shampooing using water is not an option, it does not clean as thoroughly as wet shampoos. Over time, the hair will build up a residue that powdered shampoos are unable to absorb properly. For this reason, dry shampoo should only be used from time to time rather than on a daily basis.