It is also emerging as a new social media battleground for the US elections.
Earlier this month, Donald Trump joined TikTok, despite attempting to ban it on national security grounds during his presidency.
Mr Trump, who has amassed more than five million followers since launching his account on Saturday, said he will use “every tool available to speak directly with the American people”.
President Joe Biden is also using the platform to campaign for re-election in November, but he has only picked up around 350,000 followers – far fewer than his rival.