Science, Tech, Math › Science How Dry Shampoo Works to Refresh Hair What Is in Dry Shampoo? Share Flipboard Email Print Dry shampoos typically are applied to the oily roots of the hair and brushed out. It's important to avoid rubbing the shampoo into the scalp, as this can cause itching and dry skin. ElenaNichizhenova, Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated July 01, 2019 Dry shampoo cleans and refreshes your hair on days you can't use traditional shampoo and water (or choose not to). Here's a look at whether or not dry shampoo actually works and what it does. Key Takeaways: How Dry Shampoo Works Dry shampoo is a product that is applied to hair to reduce oiliness without the need for water.Most types of dry shampoo include a starch, usually from corn or rice, as a key ingredient. The starch absorbs oil and drops away from hair during brushing.Since some product inevitably remains in hair, a dry shampoo can cause hair to feel thicker.While dry shampoo helps improve the appearance of hair, some users dislike the texture it adds to hair.Dry shampoo is not a permanent substitute to washing hair with soap or shampoo. This is because dry shampoo does not remove shed skin cells or control bacteria. What Is Dry Shampoo? Dry shampoo is a powder or a fast-evaporating liquid that your spray or work into your hair that removes excess sebum and other oils and may freshen the scent of your hair. Commercial products contain much the same type of ingredients as homemade dry shampoo, although dry shampoo from a store is more likely to have a uniform texture than a product you make yourself. Both dry and spray-on dry shampoos work the same way. Why Use a Dry Shampoo? Aside from the obvious situation where water isn't available, you may wish to use a dry shampoo for any of the following reasons: Reduces stripping of color by traditional shampoosExtends the life of an expensive blow-outMakes hair easier to styleTakes less time than washing and drying hairMinimizes hair damage since natural protective oils aren't strippedFreshens hair if you're coming from a smoky, sweaty, or otherwise smelly situation How Dry Shampoo Works Dry shampoo and wet-dry shampoo works by absorbing oil onto a substance that can be brushed or blown out of your hair. The two main types of dry shampoo are homemade and commercial. Oil-absorbing ingredients you can use to make homemade dry shampoo include corn starch, baby powder, rice starch, orris root, oatmeal, and clay. Feel free to add a couple of drops of lavender essential oil to one of the powders to add a fresh scent. If using baby powder, be sure to use a brand free of asbestos (a common contaminant). Clay, while excellent at controlling oil, may also be contaminated with metals or undesirable minerals (so don't just dig it up from your garden). Because brands don't exactly advertise impurities, it's probably safer to stick with corn starch, rice starch, orris root, oatmeal, or some mixture of the these ingredients. Commercial brands typically contain some form of starch, fragrance, and a propellant to help apply product evenly over hair. Some products contain an anti-clumping agent to help disperse particles. A popular commercial spray-on dry shampoo contains isobutane, propane, denatured alcohol, aluminum starch octenyl succinate, butane, fragrance, isopropyl myristate, silica, and cyclopentasiloxane. Only hydrophobic soils, like natural oils and oil-based styling products, are absorbed by the dry shampoo. Dry shampoo will not remove actual dirt, skin flakes, and other chemicals that can make hair look and feel greasy, so most stylists recommend using dry shampoo between regular shampoos to reduce chemical damage to hair or for unexpected emergencies. Most people still need to use regular water-based shampoo to get fresh, clean hair. Dry Shampoo for Animals Dry shampoo isn't just for people! Dry shampoos may be used on furry pets. Commercial pet products are a bit different from ones intended for humans. They may contain conditioning agents, Melaleuca oil to repel fleas, or even pesticides. Pet products may be powder or foams. The shampoo must be worked into the animal's coat and then wiped off. Dry shampoo should be used with caution on cats because they lick themselves and will ingest some product. Learn More If you're ready to give dry shampoo a try, make one of these easy homemade dry shampoo recipes. If you're not ready to take the plunge, but are concerned about ingredients in commercial products, make homemade shampoo and learn exactly how shampoo works.