If you value the homeostasis of your mind, and specifically, it's dopamine circuits, you may want to seriously consider not using tiktok, _ever_.
I know that's not what your question was. However, consider the following.
TikTok is a computer program and service that was created by the Chinese. The Chinese Communist Party literally enforces rules and limits on how much their younger population is even allowed to use certain programs and internet services, as well as video games. So, they obviously value the well being of the minds they seek to develop through their institutions of learning. They want to see their young well educated and not getting hooked into fruitless activities. Politics aside...
The thing to consider there is that, they don't seem to care about what you, as an american do with your mind; and most american companies don't care either.
Consider also the latest research on how dopamine works. Dopamine is not a reward chemical, as it was once thought to be in the erroneous neurochemical addiction model. The dopamine circuit is a motivational circuit.
If you take a mouse, which they have done, and provide it with some kind of reward, if it presses a lever, it has been observed several things can occur.
1: If you have the lever give a reward, nearly every time, it is unlikely the mouse will engage in a lot of lever pressing, it knows a reward will come, so it just takes the reward when it feels like it.
2: likewise, if the lever only gives a reward 10% of the time or so, the mouse does not engage in a lot of lever pressing, it gives up on the idea of ever getting rewarded.
3: this third outcome is the imporant observation. If the lever is designed to give a reward only 30-40% of the time, the mouse begins pressing the lever like crazy, constantly seeking a reward. It does this because it never knows when it will get one, because the odds are just low enough, that it doesnt' happen often; but, not high enough that it can happen with any degree of knowable _certainty_ (this could be called the _slot machine effect).
Programs like tiktok are _specifically_ designed around this new research. The way they have designed it, is NOT, for your benefit, it is for THEIR benefit; and how have they designed it? To keep you pressing that lever, over, and over, and over (more specifically, _swiping_ over and over and over.)
Consider then, the following.
Tik Tok vidoes are short. All you have to do to see the next one is swipe. It is unlikely that either 90%-100% of the videos you encounter you will like, and it is also unlikely that 0%-10% of the videos you see you will like. So what is the result? The program reinforces dopamine production to elicit a specific behavior. What is the behavior they want to elicit? More swiping, and more viewing. What is the result? You spend more time on the program. What is the result of that? You produce more and more dopamine to motivate you to seek out more and more videos of which you will enjoy. And the result of that, is more time spent swiping and watching short videos. And what is the result of this circular, self-reinforcing behavior? Your motivational circuit is altered.
The dopamine itself isn't the reward, it's the chemical your brain uses to communicate more energy and resources to motivate you to complete a task/goal in the aim of achieving something, or acquiring something. It's motivating you to find a reward.
And what is the reward? Another cute video? Another funny video? Another interesting video? _a short video_ nothing more, and nothing less. They have psychologically programmed and engineered tiktok in such a way as to chemically induce and reinforce your using it. They also do this in video games now with, 'loot boxes.' You never know what you'll get; but, you'll get something decent, _just_, enough, to reinforce you seeking out more loot boxes. This practice has actually been banned in europe for being gambling.
Are short little videos bad in their own right? No. A lot can be said with a little. Examples of this would be quotations, trailers for movies, a movie clip to convey something, a short news clip, etc.. etc.. But one can not subsist on a diet of one liners, movie trailers, and summaries. You can't learn chemistry in 2 minutes. You can't read shakespear in 2 minutes. And if you train your brain, repeatedly, through reinforcement, to seek out the type of rewards that come easy, within seconds or minutes; your ability to plan and execute greater strategies and more long term goals, will atrophie and diminish.
Don't let corporations exploit your mind. It may be nearly impossible to avoid that happening these days; but, it's better to be aware of it, then to not be.