Thousands of women in Britain, who are eager to have bigger bottoms, are said to be risking their lives by taking pills that have been designed to fatten up chickens.
The poultry tablets are packed with hormones that have been linked to breast cancer and liver problems in humans, the Sun reported.
They were originally used by farmers to bulk up chickens, but it was discovered that when taken by women they enhance the size of thighs, hips and bottom.
Now scores of online sites are also offering "herbal" versions of the tablets with names like Star Curves, Big Beautiful Butt Formula, and Brand New Booty pills.
They are featured on sites including Amazon, eBay and Facebook and are also advertised on reality TV star Kim Kardashian's blog.
Makers of the herbal pills claim the capsules only contain exotic plant extracts, which mimic the effect of fat-building hormones.
But medical experts have warned many of the pills are unregulated and those who take them cannot be sure what they contain.