Advertisements on Facebook and Twitter may soon come with side effects. The Food and Drug Administration is currently reviewing its policies on how to regulate pharmaceutical advertisements on social networks, BuzzFeed reports.

The FDA began a public call for comment on what it calls “Character-Space-Limited Online Prescription Drug Communications,” or advertisements aimed to promote drugs and therapies that would appear on social media.

According to the listing from the FDA, “the objective of this research is to test whether a link to prescription drug risk information can effectively convey the risks associated with a drug when benefit claims about that drug are made within character-space-limited communications used in prescription drug promotion.”

This presents a considerable challenge for drug companies under current policies, which require require drug makers to disclose the potential health risks associated with their products.

In traditional advertising, this is generally accomplished via disclosures printed in small font in advertisements in traditional media or read at auctioneer speed at the end of a television or radio advertisement.

Accomplishing the same effect is trickier when placing an ad on Facebook or Twitter. With character limits applied, it would make it difficult to include the lengthy side effects of a product.

The issue manifested itself when Kim Kardashian shared an Instagram post promoting a morning sickness drug. She was paid for the sponsored post and linked to the product in the photo caption, but failed to include a full disclosure of the potential risks of the drug. The post earned the drug manufacturer a warning from the FDA.

Kardashian removed the post before reposting it with side effects listed.

The appeal of posting ads on social media sites is obvious for pharmaceutical companies; sites like Facebook and Twitter provide a platform that makes it easy to target potential customers. Because of the wealth of user information gathered by social networks, it’s possible for advertisers to target users based on interests, demographics, and other specific details.

Social networks will likely help accommodate advertisements from drug makers in hopes of grabbing a portion of the $6 billion spent on advertising by pharmaceutical companies in 2015. Facebook, for example, presented safety information on an ad placed by Bayer with an auto-scrolling line of text.

The FDA will be collecting public feedback on pharmaceutical advertising on social media through Jan. 6, 2017.