Horse shampoo … because I'm worth it

Black Beauty, it seems, has been keeping something from us.

All that flicking and swishing of glossy mane – and not a single mention of the miracle product responsible.

But now, the secret is out. Mane'nTail is a shampoo formulated for use on horses' hair – which is dry, frizzy and three times thicker than human hair.

The results were so spectacular that horse owners began to use it on themselves.

And before long a cult beauty product was born, with manufacturers tweaking the formula to suit human hair.

Celebrity converts reportedly include Sarah Jessica Parker and Jennifer Aniston.