Did Kim Kardashian violate the Food and Drug Administration's marketing regulations with a social media post about morning sickness medication?

According to a warning letter from the FDA to pharmaceutical company Duchesnay, Kardashian's July Instagram post that its drug Diclegis cured her morning sickness ran afoul of the agency's regulations.

Text accompanying a photo of the reality star holding a bottle of Diclegis read: "OMG. Have you heard about this? 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. I'm so excited and happy with my results that I'm partnering with Duchesnay USA to raise awareness about treating morning sickness. If you have morning sickness, be safe and sure to ask your doctor about the pill with the pregnant woman on it and find out more www.diclegis.com; www.DiclegisImportantSafetyInfo.com."

In a letter from the division director of the FDA's Office of Prescription Drug Promotion, Robert Dean, the agency said the social media posts (Kardashian's Instagram is linked to her Facebook and Twitter accounts) were false and misleading in violation of the Food, Drug and Cosmetic Act.

While Kardashian highlighted the positive benefits of Diclegis, she failed "to communicate any risk information associated with its use" and omitted material facts, Dean wrote. "These violations are concerning from a public health perspective because they suggest that Diclegis is safer than has been demonstrated."

The post misbranded Diclegis in two ways, the FDA said. First, the post "entirely omits all risk information," and the suggestion to visit the drug's website "does not mitigate the misleading omission of risk information." Secondly, the post failed to provide material information about Diclegis' approved indications, including an important limitation that the drug has not been studied in women with hyperemesis gravidarum.

Of particular concern to the FDA is the fact that this wasn't the first time the agency has written to Duchesnay about misbranding Diclegis. The pharmaceutical manufacturer received a similar letter from the agency in November 2013 regarding promotional activities that omitted all risk information and material facts about Diclegis' limitation of use.

Duchesnay should immediately stop misbranding the drug, the agency wrote, and provide the FDA with a plan for discontinuing the use of such promotional materials. Given the company's prior history of misbranding, the company must further submit "a comprehensive plan of action to disseminate truthful, non-misleading, and completely corrective messages" about the issues discussed in the letter.

To read the FDA's warning letter to Duchesnay, click here.

Why it Matters: Despite the FDA's action, Kardashian's high-profile social media presence has already given Duchesnay and Diclegis a sizable boost. The Instagram post at issue—which has since been removed from the reality star's account—gathered 450,000 likes and Treato, an Internet-based intelligence company that analyzes social media, found that the drug got a 500 percent increase in digital activity in July. Although Kardashian herself is out of the reach of the FDA, the Federal Trade Commission could decide to make an example of the situation and take action against her as an endorser.