Cocamidopropyl hydroxysultaine is a synthetic ingredient that is a member of the hydroxysultaine group of ingredients. In skin care and other personal care products, cocamidopropyl hydroxysultaine functions as a surfactant, foam booster, thickener, and anti-static agent.

Cocamidopropyl hydroxysultaine functions as a surfactant because it contains one end that is hydrophilic (attracted to water) and one end that is lipophilic (attracted to oil). Surfactants work by lowering the surface tension between two substances, such as two liquids or a liquid and a solid. This allows surfactants to attract and suspends oils, dirt, and other impurities that have accumulated on the skin and wash them away. Due to these properties, cocamidopropyl hydroxysultaine can be found in many different cleansers, shampoos, and body washes.

Another reason cocamidopropyl hydroxysultaine is often used in cleansing products is due to its foam boosting effects. Foam is formed when air is dispersed in a continuous liquid medium. Surfactants like cocamidopropyl hydroxysultaine help stabilize the air bubbles that are surrounded by thin layers of liquid, creating foam. Lastly, cocamidopropyl hydroxysultaine can be used as a thickener and also to reduce or eliminate buildup of static electricity.