how-shampoo-became-a-million-dollar-idea

Two centuries ago, it was used only by Indians. Nowadays, billions of us use it every day. We’re talking about shampoo. The world lathers its way through almost $90bn-worth a year.

But who made it the global way of washing hair? And do we really need to use so much of it? Here’s Aaron Heslehurst.

Video journalist: Jeremy Howell