Lather, rinse, and repeat are just a few simple steps we follow when washing our hair. The shampoo goop we squeeze from the bottle, use our hands to caress our locks with, and work our way into a lather is specifically designed to treat our hair follicles, but how exactly does it work? Mental Floss’s host Craig Benzine explains in the video “16 Shampoo Facts (Incl. Why There's Silicone In Your Shampoo!)” how shampoos came to be and how they’re formulated to keep our hair healthy.

Shampoo contains surfactants — two-faced chemical compounds that clean our hair — which lower the surface tension of water. This makes it less likely to stick to itself and able to bind with oils and soiling parts in our scalp. Half of each surfactant wants to dissolve in water and the other half wants nothing to do with water. Therefore, when hair meets water that has interacted with these surfactants, it includes sebum, dirt, and grime that is washed away with the lather.

Most commercial shampoos contain silicone meant to keep our hair feeling healthy. Polymers like silicone are added to all sorts of shampoos to safely recoat the hair cuticles after they’ve been cleaned. The coating smoothes them down and adds a lubricating and protective sheath. Shampoos that cater toward volume, shine, or UV ray protection all contain different polymers that strictly serve this purpose.

When it comes to haircare, it’s important to remember not all shampoos are created equal. Shampoo found in the U.S. is slightly different from the same stuff found in other countries. Since water quality fluctuates depending on location, shampoo makers adjust their formulas so water and surfactants can interact accordingly. For example, hard water has a higher mineral and deposit content that can overwhelm a surfactant; therefore, other chemicals have to be added to the shampoo to counteract the ions that make the surfactant ineffective.

Remember, don’t forget to lather, rinse, and repeat at least two to three times a week for clean and healthy hair.

Click on the Mental Floss video above to learn more about shampoo and its unusual applications in everyday life.