(Gonzalo Fuentes/Reuters)

When Kim Kardashian tweeted and instagrammed her enthusiasm about a morning sickness treatment, her words of praise were a direct pipeline to tens of millions of followers.

“OMG. Have you heard about this? As you guys know my #morningsickness has been pretty bad,” the celebrity wrote on an Instagram post that she also linked to on Twitter late last month. Kardashian has more than 34 million Twitter followers and 42 million Instagram followers.

But that social media post of Kardashian’s glowing cheek next to a pill bottle of DICLEGIS, made by Duchesnay USA, also drew the attention of federal regulators. In a letter dated Aug. 7, the Food and Drug Administration has ordered the company to take it down.

“The Office of Prescription Drug Promotion … has reviewed the Kim Kardashian Social Media Post,” the letter begins, ominously. "The social media post is false or misleading in that it presents efficacy claims for DICLEGIS, but fails to communicate any risk information."

The letter notes that the label of the drug, which describes its approved uses, includes important limitations on the use of the drug which Kardashian neglected to bring up online. The drug hasn't been studied in women with a rare complication of pregnancy that causes extreme morning sickness. It's actually not recommended at all for women sensitive to various drugs. And the drug label comes with warnings and precautions for activities requiring mental alertness. Somehow, that also failed to be mentioned.

“The social media post, however, entirely omits all risk information,” Robert Dean, division director of the Office of Prescription Drug Promotion wrote.

Laney Landsman, a spokeswoman for Duchesnay, said that Kardashian is a paid spokeswoman for the company and confirmed that the Instagram post was removed immediately.

"Duchesnay is working very hard to take quick action in responding to the FDA’s letter and are working out a plan to submit to the FDA," Landsman said.

Social media has made life ever more difficult for the regulators who try and ensure that companies don’t “misbrand” drugs, making claims that go beyond what they are approved to do. In a Q&A, Thomas Abrams, the director of the Office of Prescription Drug Promotion, described how that changes the workflow and the speed.

"The Internet and social media have increased the volume and extent of materials and speeded the delivery of those materials. Web sites can have hundreds of pages and can change daily,” Abrams said.

The issue of direct-to-consumer advertising on social media is complicated due to things like character limits, which may restrict how many side effects or limitations of a drug can be listed. The FDA has released guidance on the topic, but Kevin Madagan, counsel at Reed Smith, said that companies have generally been wary about using social media to promote prescription drugs due to the disclosures that have been required in other mediums. Think: that long list of side effects that are rushed into the end of a TV commercial.

"Outside of a promotional context, Kim Kardashian, if she jumped on Twitter and made these statements, and had absolutely no relationship to the company, that would be fine," Madagan said. "You need to be careful about how you go about doing it. Certainly, in my opinion, doing it in this manner [is risky] — have a paid spokesperson take the leap in doing something like this. There’s really no attempt at all to provide risk information in this post."

Landsman said the company is now working directly with FDA in order to make promotional materials that are not misleading. The company is required to correct the misperceptions that the original post created. Does that mean FDA will have a heads-up on what Kardashian's next tweet will say?