(ABC NEWS) - You can lose weight fast - all you have to do is pop a pill or try a berry.
There are products all over the Internet, claiming they've been endorsed by the famous Dr. Oz.
Dr. Oz, though, was the one on the hot seat Tuesday, in front of lawmakers on Capitol Hill who grilled him about potentially "deceptive" ads for so-called weight loss products.
"Take this pill, drink this shake, use this device, or apply this cream," paraphrased Senator Claire McCaskill Tuesday. "All without adjusting diet or increasing physical activity."
Americans spend $40 billion a year on weight loss products, she said - and the Democratic senator focused on false and deceptive advertising for some of the products Tuesday on the Hill.
"Dr. Oz" - or Dr. Mehmet Oza - is a cardiothoracic surgeon who became a household name with his popular daytime television show that focuses on health and wellness issues.
On Tuesday, lawmakers spoke of what they call "the Dr. Oz effect" when it comes to products - for example, sales of Neti pots spiked over 12,000 percent after appearing on his show recently.
McCaskill showed a clip from one of Oz's commercials in which he says, "It's green coffee beans, and when turned into a supplement, this miracle pill can burn fat fast. It's very exciting and it's breaking news."
McCaskill said viewers trust Dr. Oz, and when he makes statements like that, they pay attention.
"I am concerned that you are melding medical advice, news and entertainment in a way that harms consumers," she said.
Last month, the Federal Trade Commission said it was suing the Pure Green Coffee Company for using false weight-loss claims and fake websites to market its product after getting a big boost from the Dr. Oz show.
Oz insists he does not endorse any products, nor does he receive any money from the ones that appear on his show.
"If you see my face or my picture or anything from my show in an advertisement - do not buy the product," he told lawmakers Tuesday.