Head & Shoulders is a brand

Brand

The American Marketing Association defines a brand as a "Name, term, design, symbol, or any other feature that identifies one seller's good or service as distinct from those of other sellers."...

 of anti-dandruff

Dandruff

Dandruff is the shedding of dead skin cells from the scalp . Dandruff is sometimes caused by frequent exposure to extreme heat and cold. As it is normal for skin cells to die and flake off, a small amount of flaking is normal and common; about 487,000 cells/cm2 get released normally after...

 shampoo

Shampoo

Shampoo is a hair care product used for the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair...

 produced by Procter & Gamble

Procter & Gamble

Procter & Gamble is a Fortune 500 American multinational corporation headquartered in downtown Cincinnati, Ohio and manufactures a wide range of consumer goods....

. Head & Shoulders Classic Clean Shampoo is the top-selling shampoo in the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 by dollar sales.
Matt Elliott got Procter & Gamble researchers to start making a new anti-dandruff shampoo in 1950. Nearly a decade of research went into making a new formula, which introduced pyrithione zinc into the shampoo.

Head & Shoulders was first introduced to the U.S.