If you struggle to tame coarse, straw-like hair, forget expensive potions and smoothing serums.
A rather more basic product is proving a winner on the High Street - a shampoo for horses.
Mane n' Tail was created to keep show ponies' coats looking glossy and healthy. But more and more women are turning to the product to achieve thick, lustrous locks of their own.
Liberty in London began stocking it three years ago and word of mouth has turned it into the Regent St store's best-selling shampoo. Now, Urban Outfitters has become the first high street chain to offer the product on its website and in some of its 238 UK stores.
The shampoo has a host of celebrity backers, including reality TV star Kim Kardashian and actress Jennifer Aniston, and it has received glowing reviews online. Anna Marie, from Illinois in the US, wrote on Mane n' Tail's Facebook page: "I love the shampoo and conditioner! I had issues with my hair falling out but since I have begun using this product line, my hair has almost completely stopped falling out! I also bathe my cat, dog, and horse with this shampoo and they look great afterwards!"
Veronica Cox, from the UK, wrote: "Love this product, makes you hair look fuller." Urban Outfitters' website says Mane n' Tail is "loved by humans and horses alike".
Sarah Coonan, Liberty's beauty buyer, said: "Mane n' Tail is the original horse-to-human crossover brand.
"It leaves your hair clean and shiny without stripping any natural oils. Our customers love it too, it's Liberty's best-selling shampoo."
Mane n' Tail was created by the Katzev family, who own a horse farm in New Jersey, for show ponies with "long flowing manes and tails".
Devon B. Katzev, president of the brand's parent firm Straight Arrow, said the crossover happened when horse owners started using the products on their own hair and word "spread like wildfire". He added: "Our original formula [has] been a best-kept secret for beauty aficionados everywhere."
Liberty and Urban Outfitters are selling Mane n' Tail shampoo and its conditioner for £7 (NZ$14.60) each.