TikTok has been charged by the European Commission with failing to protect users’ mental health by exposing them to a relentless stream of content that risks worsening eating disorders and anxiety in a case that strikes at its business model.

Issuing a preliminary ruling on Friday, the EU regulator said TikTok’s algorithm “can be harmful” and was leading young and vulnerable users “down rabbit holes they cannot easily escape from”.

The Chinese-owned short-video platform, which has 189 million users in the EU, was found to have failed to prevent users from being served up repetitive content on themes such as body image or isolation, which can lead to anxiety, sadness, worsen existing eating disorders or mental health problems.

Officials said their investigation focused on legal content, where a single video might not be problematic, but the cumulative effect of watching scores of them on one theme could damage users’ mental health.

TikTok’s safeguards to mitigate the risks of “rabbit-hole effects” – where users are served narrow and repetitive content to keep them engaged – were found to be ineffective. For example, officials said, if a user checked a “not interested” button on a video about eating patterns, the algorithm would still offer them similar content on diet and body image. Similarly, refreshing a feed only provided a brief respite from a stream of content on one topic, it found.

“Every time a user scrolls or likes a video on TikTok, the algorithm serves more of the same leading users down rabbit holes they cannot easily escape from,” said the European Commission’s lead official on tech policy, Henna Virkkunen. “TikTok needs to step up its efforts to protect users’ wellbeing, including those of minors.”

In response, a TikTok spokesperson said: “The commission has made a series of statements that are fundamentally inaccurate and distort our platform’s architecture and our commitment to user safety.

“We have a strong record of protecting our community while giving users direct and intuitive control over their content experience.”

The company argues that its policies prohibit content that promotes disordered eating and risky weight-management behaviours. It also says that more than 79 million users in the EU used its “not interested” or keyword filters to screen out unwanted content in the first six months of 2026.

The Molly Rose Foundation, which was set up in memory of 14-year-old Molly Russell, who took her own life in 2017 after being exposed to a torrent of harmful online content, welcomed what it called the landmark findings “to seek to hold TikTok to account for the way their algorithm drives young people down rabbit holes of despair”.

A survey for the charity earlier this year found that nearly half of girls and a third of all UK teenagers saw suicide, self-harm and eating-disorder content on social media in a week.

The foundation called on the UK regulator, Ofcom, to open an investigation into TikTok’s “extremely damaging” algorithm.

The EU investigation strikes at TikTok’s business model, which is built on keeping users scrolling as long as possible.

EU officials want TikTok to change the design of its ForYou feed, to give users greater control over the content they see.

“We are addressing a business model,” a commission official told reporters, saying that a business model focused mainly on engagement “can potentially create a risk” especially for minors and vulnerable adults.

The findings are part of a broader investigation launched in February 2024 under the Digital Services Act, which obliges large internet companies to take action to prevent a wide range of harms, from disinformation to damage to mental health.

The commission has already found the company violated EU rules over its “addictive design” for features such as infinite scroll. The company said at the time “the commission’s preliminary findings present a categorically false and entirely meritless depiction of our platform” and that it would challenge the findings.

A complaint about lack of transparency over who paid for TikTok’s advertising was resolved when the company made binding commitments to change its policies last December.

TikTok, which now has a chance to examine the investigation file and mount a defence, could agree to change its recommender system to avoid a fine.

If EU officials uphold the finding, the company could be fined up to 6% of its global worldwide turnover.

• In the UK and Ireland, Samaritans can be contacted on freephone 116 123. In the US, you can call or text the 988 Suicide & Crisis Lifeline at 988 or chat at 988lifeline.org. In Australia, the crisis support service Lifeline is 13 11 14. Other international helplines can be found at befrienders.org