Kevin Burns, chief executive of vaping firm Juul, has stepped down, amid growing concerns around vaping health risks and criticism of its marketing.
The firm has announced it will withdraw all US advertising.
Mr Burns will be replaced immediately by KC Crosthwaite, former chief growth officer at tobacco giant Altria, Juul said.
Juul is 35%-owned by Altria, and in the past has been accused of targeting vaping devices at children.
Mr Burns said: “Since joining Juul Labs, I have worked non-stop, helping turn a small firm into a worldwide business, so a few weeks ago I decided that now was the right time for me to step down.”
The firm has been popular with investors, and filed documents in August showing that it had attracted $325m in funding.
However, there is growing concern about the health risks of vaping, and the effects of its marketing.
The US authorities are investigating a spate of serious lung injuries linked to vaping.
On 9 September, the US Food and Drug Administration said it had issued a warning letter to Juul over its marketing activities, including “a presentation given to youth at a school” as well as activities “targeted at students, tribes, health insurers and employers.”