Scientists say they have identified the difference between straight and curly hair.

They believe it could lead to drugs that can make straight hair curly and vice versa.

Scientists also believe the discovery could lead to the death of hair dyes, as drugs could be used to restore colour in the prematurely grey.

In Clichy, Paris, a team from L’Oreal grew hair in the laboratory to get to the root of what makes hair curly or straight.

They found that the hair bulb, around four millimetres deep in the scalp, is hook-shaped in people with curly hair and straight in the case of European and Asian hair.

When it emerges from the scalp, the hair shaft retains the shape of the follicle.

“A curly follicle makes curly hair,” said Bruno Bernard, head of hair biology at L’Oreal. “This is a breakthrough. For a very long time people did not understand how hair got curly.”

Although the team has yet to find a “master switch” that controls follicle shape, Mr Bernard said it was now possible to think about how to change hair shape by using hormones or drugs.

“It is now possible to use biological methods to make curly hair straight and vice versa,” he said.

More here.