• by Wendy Davis , Staff Writer @wendyndavis, August 12, 2015

On July 19, pregnant celebrity Kim Kardashian took to Instagram to praise the morning-sickness drug Diclegis to her 42.6 million Instagram followers.

"OMG. Have you heard about this?" she wrote. "As you guys know my #morningsickness has been pretty bad. I tried changing things about my lifestyle, like my diet, but nothing helped, so I talked to my doctor. He prescribed me #Diclegis, and I felt a lot better and most importantly, it’s been studied and there was no increased risk to the baby."

The reality TV star, who has long been paid for her tweets, added that she was so "excited and happy" with the drug that she was partnering with the manufacturer, Duchesnay USA, to "raise awareness about treating morning sickness."

Her post goes on to direct people to consult with their doctors and to visit the company's Web sites for more information.

The Food and Drug Administration took a dim view of the Instagram message, which flouted the agency's long-established requirement that ads touting the benefit of drugs also disclose their risks and contraindications.

"By omitting the risks associated with Diclegis, the social media post misleadingly fails to provide material information about the consequences that may result from the use of the drug and suggests that it is safer than has been demonstrated," Robert Dean, Division Director of the FDA's Office of Prescription Drug Promotion, wrote in a warning letter to Duchesnay Executive Vice President Eric Gervais.

Among other risks, the drug contains warnings regarding "activities requiring mental alertness," and can cause drowsiness.

He gave the company until Aug. 21 to respond to the warning and come up with a plan to "disseminate truthful, non-misleading, and complete corrective messages."

While the FDA's letter was addressed to the pharmaceutical company, the warning raises questions about whether Kardashian herself could face any problems with regulators.

The FDA can only take action against drug companies, but the Federal Trade Commission potentially could accuse Kardashian of misrepresenting the drug in an ad.

The FTC has repeatedly said that its rules against misleading ads apply to campaigns on social media. For instance, last November the FTC alleged that ad agency Deutsch LA engaged in a deceptive practice with an ad campaign that involved asking employees to promote Sony's PlayStation Vita on Twitter. The posts, which ran in 2012 and carried the hashtag #gamechanger, allegedly didn't indicate they came from Deutsch employees. (Deutsch LA agreed to settle the charges by promising that it won't in the future misrepresent the features of handheld gaming consoles, and will disclose any material connections between an endorser of a game and the marketer.)

While the FTC has not yet targeted any individual bloggers (or Tweeters or Instagram users) for making promotions on social media, Kardashian could well be the first, says Linda Goldstein, an advertising attorney with the law firm Manatt, Phelps & Phillips.

One reason is that Kardashian's statements about the drug's safety might have "overstated the science," says Goldstein.

Another is that the celebrity's language about "partnering" with Duchesnay might not make it clear that she's serving as a paid endorser, Goldstein says.

Whether the FTC will act remains to be seen. For now, however, Kardashian's post is no longer on Instagram, although a Tweet referencing it was still available on Wednesday afternoon.