Shaquille O'Neal swears by them.The power balance , he says, gives him a competitive edge on the court. It's no gimmick, he says. It's for real.
But Australian authorities say the California-based company behind the wildly popular wristbands and pendants has no business claiming that they improve balance, strength and flexibility.
And they even got powerbalance to admit there was "no credible scientific evidence" to support their claims.
The bracelet manufacturers also agreed to give refunds to customers who believe they have been cheated.
The admission has hopped across the globe since its agreement with the Australian Competition and Consumer Commission was announced on December
It was an answer to what many who saw the ads wondered: Do the colourful silicone bands actually work?
Critics railed against the company on Twitter and those who had believed in the bracelet's power.
The company unleashed a torrent of its own tweets, however, playing off the word "admit".
In one, it said: "Power Balance Admits products have been worn during the last world series, NBA finals and super bowl champions!"
Fans insist the bands have helped their game.
"Our trainers swear by it," Phoenix Suns forward Jared Dudley wrote in a message posted on his Twitter page.
The company began selling bracelets in 2007 embedded with holograms that were purportedly designed to interact with the body's natural energy flow.
Since then, the colourful wristbands, which sell for US 3.99), have become ubiquitous, donned by Los Angeles Lakers' Lamar Odom and English celebrity soccer star David Beckham.The programme even thought about putting its logo on the products, but decided they couldn't find enough reliable research to back up the company's claims about giving a biological boost to performance, he said.
"I couldn't look in the mirror and 100 per cent say [it's] a product I can put my brand reputation behind,"
Wisconsin sports science professor John Porcariran ran tests comparing the performance of 42 athletes wearingpower balance bracelet and silicon versions from Wal-Mart and said he found no difference.
"I think it is a scam. It is all in people's heads."
They have also been worn by celebrities, including actors Robert De Niro and Gerard Butler.
The company sold US$8000 of merchandise in its first year and expects more than US$35 million in sales during 2010.
Power Balance, for its part, doesn't claim to have science on its side, said Adam Selwyn, a spokesman for the California-based company.
Rather, it relies on testimonials from famous athletes and users to tout the products' effects. The company says it pays some athletes for the right to use their images wearing the bracelets, including O'Neal and Odom.
Josh Rodarmel, one of the company's co-founders, said in a statement he knows there may be sceptics. "We're not trying to win over every person in the world, he said.
Ralph Reiff, programme director at St Vincent Sports Performance in Indianapolis, said maybe a third of the athletes who train there wear the wristband or an imitation.