Inventing a product that is wildly popular is not usually a setback for a technology company. But that is the difficulty facing Juul Labs, the San Francisco start-up behind the best-selling US ecigarette.

Juul is the Nespresso of vaping — a sleek device that works with a collection of flavoured pods, including mango and cucumber, to deliver an intense hit of nicotine in a cloud of vapour. It mimics so well the pleasure of smoking that “Juuling” has become a craze among teenagers and taken 72 per cent of the US ecigarette market. The company, which was founded three years ago, is now valued at $16bn.

Juul Labs is in trouble with the US Food and Drug Administration, which does not want to get fooled by the industry again. Tobacco companies hid the harmful effects of smoking for decades and the FDA is under intense pressure not to let ecigarette use turn into a similar scandal. It has threatened to curb adults’ freedom to vape if companies such as Juul cannot keep ecigarettes away from under-18s.