Kim and Khloe Kardashian are reportedly facing a lawsuit over the diet product they endorse, QuickTrim. The New York Post reported that a law firm is preparing to sue the product manufacturer Windmill, and the Kardashians for their marketing claims.

A partner from the firm said, "My firm has been retained by an individual that purchased QuickTrim, and we are investigating the matter. We have provided written notice of our client's claims to the company and others involved in marketing QuickTrim."

The issue is that QuickTrim contains high levels of caffeine, an ingredient that's "not safe or effective for weight loss." It has reportedly generated $45 million in revenue since the Kardashians began promoting it.

In 2010 a physician said of the product, "They're not saying how much caffeine is in these pills. Too much caffeine can make you jittery and increase your blood pressure and pulse. If you pop a couple of these pills with your Starbucks . . . you could get caffeine poisoning, which can cause heart arrhythmias."