Dr. Ben Carson reportedly endorsed and give speeches on behalf of medical supplement maker Mannatech, Inc. while he was employed at Fox News, an apparent violation of the network's stated policy prohibiting “any on-air talent from endorsing products or serving as a product spokesperson.”

Fox News hired Carson in October of 2013 and cut ties with him in November of 2014 as he reportedly began exploring a campaign for the Republican presidential nomination.

National Review reports that in March of 2014, while still working at Fox, Carson appeared in a video for Mannatech, promoting its line of “glyconutrient” products.  In the video, Carson talks about his 10-year use of the company's products, noting, “The wonderful thing about a company like Mannatech is that they recognize that when God made us, He gave us the right fuel. And that fuel was the right kind of healthy food.” Carson also made speeches at Mannatech events in 2011 and 2013.

According to the conservative magazine, “Mannatech has a long, checkered past, stretching back to its founding more than a decade before Carson began touting the company's supplements.”

Fox has previously said that it bars its personnel from such activities. In 2009, in response to the controversial relationship between then-Fox News employee Glenn Beck and Goldline, Fox released a statement to the New York Times that said, “Fox News prohibits any on-air talent from endorsing products or serving as a product spokesperson.” Former Fox contributor Tobin Smith was fired in 2013 for a violation of this policy (though fellow contributors Charles Payne and Keith Ablow have engaged in similar behavior without repercussions).

When asked by National Review about Carson's relationship to Mannatech, Carson's business manager Armstrong Williams said, “I don't know that he's ever had a compensated relationship with Mannatech” and said that the Washington Speakers Bureau, which had booked “hundreds of speaking engagements for him through the year, booked these engagements.”

Mannatech was sued by Texas' attorney general, who accused them of using marketing that has exaggerated the health benefits of their products. The company later paid a $4 million settlement without admitting wrongdoing.