All shampoos contain surfactants. The question isn’t whether — it’s which. Surfactants are classified by how aggressively they bind to oil and how they behave on the hair’s protein and lipid surface.
The aggressive family is the sulfate group (SLS, SLES, ammonium lauryl sulfate). They strip efficiently — too efficiently for most hair types.
The gentle family is long and growing: cocamidopropyl betaine (coconut-derived, very mild), sodium cocoyl isethionate (excellent cleaning without stripping), decyl glucoside (plant-derived, biodegradable), sodium lauroyl methyl isethionate, and several newer synthetics. These clean through slightly different mechanisms — some charge-binding to dirt, some emulsifying oil without disrupting the protein shell — but all leave more of the hair’s natural protective lipids intact.
You want a shampoo whose first surfactant sits in the gentle family. Read the label.