At One Place

What is a Shampoo made of?

What is a Shampoo made of?
Three-quarters water, a primary detergent, a milder secondary one, salt to thicken, and silicone to make hair feel smooth.

Almost everything in a shampoo bottle is water, surfactant and conditioner; the botanical extracts on the front are usually present at fractions of a per cent. Sulfate-free formulas swap the primary surfactant for something milder such as sodium cocoyl isethionate, which lathers less and cleans less aggressively — genuinely useful for dyed or curly hair, not inherently better. Dandruff shampoos are the one category with a real pharmacological active: zinc pyrithione, ketoconazole, selenium sulfide or salicylic acid, targeting a yeast rather than dryness, and they only work if left on the scalp for a couple of minutes.

Component by component

Every material is a choice, and the third column is the constraint that drove it.
Part Material Why that material
water purified water, 70-80% The surfactants only work in solution, and the bottle is mostly the solvent — which is the whole argument for shampoo bars.
primary surfactant sodium laureth sulfate, or sodium lauryl sulfate in cheaper products It does the cleaning; laureth is ethoxylated, making it milder and less irritating than plain lauryl sulfate.
secondary surfactant cocamidopropyl betaine It stabilises foam and measurably reduces the irritancy of the primary surfactant, so it is in almost every formula.
thickener sodium chloride, or a polymer such as carbomer Salt makes surfactant micelles grow into rods and the liquid thickens — viscosity is entirely cosmetic, and cheap to add.
conditioning agent dimethicone or a cationic polymer such as polyquaternium-10 It deposits on the negatively charged hair surface and lies down the cuticle scales, which is what "smooth" and "shiny" actually mean.

Other around the house objects

Common questions

What is a Shampoo made of?
Three-quarters water, a primary detergent, a milder secondary one, salt to thicken, and silicone to make hair feel smooth.
What is the water of a Shampoo made of?
Purified water, 70-80%. The surfactants only work in solution, and the bottle is mostly the solvent — which is the whole argument for shampoo bars.
What is the primary surfactant of a Shampoo made of?
Sodium laureth sulfate, or sodium lauryl sulfate in cheaper products. It does the cleaning; laureth is ethoxylated, making it milder and less irritating than plain lauryl sulfate.

Related pages

Sources

  1. Official vendor product documentation — At One Place

How these figures are compiled and checked