TikTok is attempting to refine its 'For You' feed by adjusting how the system approaches recommendations and by giving users more control.
Plans are in motion to address the ‘For You’ recommendation feed, according to TikTok, which are intended to “safeguard and diversify.” TikTok has acknowledged that certain types of videos, when viewed in abundance, can have a negative impact on users, so it’s making changes to the way the feed works to try and fix that.
While the recommendation system tries to avoid making repetitive suggestions—such as pulling up consecutive videos by the same creator—subject matter isn't a criteria. As such, TikTok has begun testing ways to filter by content as well. The intent is to avoid recommending too much of a particular kind of content so you don't become overwhelmed by potentially harmful videos (when viewed in abundance). Examples given by TikTok include extreme dieting, breakups, and videos about loneliness.
In addition to adjusting the algorithm, TikTok is also examining the possibility of giving you the ability to create filters. This would let you set up a list of words and topics that you don't want to see and prevent such videos from being recommended to you in the future.
As for when any of these changes might be implemented publicly, we don't know for sure yet. TikTok states that it will take time to finish testing and iterating but has not offered an estimated timeframe yet.