The bloc said the platform needs to change how the For You page works to help protect users’ mental health.

The European Commission has accused TikTok of breaching the Digital Services Act (DSA) over the potentially harmful effects of the recommendation system it uses on the For You page. The European Union's regulatory arm said the personalized nature of the algorithm means that the more a user interacts with a certain kind of content, the more they see similar videos.

"This design can be harmful when such endless and repeated exposure involves, for example, content about sadness, isolation or body image," the Commission said. "These 'rabbit holes' can have a detrimental impact on users' mental health, especially that of vulnerable adults and minors."

In its preliminary findings, the regulator said TikTok didn't do enough to assess how the algorithm could draw users into these rabbit holes and put their wellbeing at risk. Nor did it put sufficient measures in place to mitigate those risks, the Commission said, noting that when a user taps the "not interested" button on a video, that "may not be enough to change the content feed."

It said TikTok has to change the design of the For You page, and that it should "rely more on users' explicit preferences, disable viewing time as an indicator to recommend content, increase the accessibility and usability of user controls, and regularly test its algorithm." If TikTok doesn't sufficiently resolve the matter in the Commission's eyes and the EU confirms the findings, parent company ByteDance could be on the hook for a fine of as much as six percent of its annual global revenue.

TikTok has refuted the claims. "The Commission has made a series of statements that are fundamentally inaccurate and distort our platform's architecture and our commitment to user safety," it said in a statement to Reuters. "We have a strong record of protecting our community while giving users direct and intuitive control over their content experience."

The preliminary findings were issued as part of a larger EU investigation into TikTok that began in early 2024. In February, the bloc said TikTok breached the DSA because of the app's "addictive design." Officials also took TikTok to task in July, claiming it failed to protect the privacy of minors' accounts.

Regulators around the world have placed social media companies under closer scrutiny in recent years, particularly over the impact their platforms have on children. This week, Google, Meta and TikTok sued California over a law that bans social media companies from allowing users under 16 to access potentially "addictive features."