The Food and Drug Administration has sent a warning letter to a drugmaker over Kim Kardashian West's endorsement of its pills for morning sickness.

Last month on Instagram, Twitter, and Facebook, Kardashian vouched for a medication called Diclegis, made by a privately held Pennsylvania pharmaceutical company called Duchesnay.

Ms. Kardashian said she was "partnering" with Duchesnay to raise awareness about morning sickness, and she urged her millions of social media followers to ask their doctors about the drug. The company later sent a press release about the partnership. (Confusingly, Ms. Kardashian also said at the Cannes ad festival this summer that her Instagram is always "off limits" to her promotional deals.)

The endorsement failed to include the necessary risk information and didn't note limitations on the drug's use. According to the FDA, that makes it misleading. The messages did include links to Web pages at which more complete safety information was available, but the regulator says this isn't sufficient. Here's a selection from the FDA's letter:

The social media post is misleading because it presents various efficacy claims for DICLEGIS, but fails to communicate any risk information. For example, the social media post includes the following claims:

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.

The social media post, however, entirely omits all risk information. We note the statement, "[F]ind out more www.diclegis.com; www.DiclegisImportantSafetyInfo.com[,]" appears at the end of the social media post; however, this does not mitigate the misleading omission of risk information. 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.

Ms. Kardashian's Instagram and Facebook posts couldn't be located at the URLs the FDA cited, suggesting that they may have been taken down. As of midday on Tuesday, a tweet that linked to the Instagram endorsement was still live:

The FDA letter, dated Aug. 7, asked Duchesnay to "immediately cease misbranding" the drug or to stop selling it. The agency gives the company until Aug. 21 to respond.

In an e-mail, a Duchesnay spokesperson said the company "acknowledges that its communications, including in social media as in this particular instance, need to be in accordance with applicable rules and regulations." Duchesnay "will take quick action in responding to the FDA's letter and immediately and effectively address any issues."

An e-mail to a publicist for Ms. Kardashian was not immediately returned.

Diclegis is indicated for women who don't respond to more conservative measures to address morning sickness, such as eating more small meals or bland foods. It is controversial because an earlier version of the compound known as Bendectin was withdrawn from the U.S. market in 1983 over fears that it could cause birth defects, though the FDA later concluded that those concerns were unfounded.

Diclegis sales have been on a steady upward climb since the FDA approved it in 2013, with about 34,000 prescriptions filled in the U.S. in July, according to Bloomberg Intelligence data -- more than double the number from the same month a year ago.

~ Bloomberg News ~