Try as she might, Brittany Kligman couldn’t free herself of a pack-a-day cigarette habit, eight years in duration. And she ached to.

She was mortified the time that a taxi driver sniffed as she entered his cab and remarked, “You’re a smoker, huh?” (And she had just showered!) She was getting more sinus infections. Because her chest felt uncomfortably tight when she exercised, she stopped high intensity interval training. Then SoulCycle classes. Finally, she quit working out.

Then Kligman, 33, tried Juul, the sleek vaping device she credits for her liberation. Since last January, it’s been hello nicotine salts, goodbye tar. Juul gave her everything she enjoyed about cigarettes — the nicotine jolt as well as something ritualised to do with her hands — but without the stink, the stigma and the carcinogens.

“The last cigarette I smoked was on July 5 when I ran out of pods,” Kligman said, referring to cartridges of mango-flavoured liquid, as she took discreet hits while chatting at a downtown Manhattan cafe. “I couldn’t finish it — it made me sick. And I thought, ‘How did I used to do this?’ “

But this week, under pressure to keep its products away from teenagers, Juul announced it was suspending sales of many of its flavours (including Kligman’s beloved mango) at retail stores. The next day, the Food and Drug Administration issued new requirements that stores can only sell flavoured e-cigarettes from closed-off spaces that are inaccessible to minors, a stipulation that could force many outlets to stop carrying the products. The new restrictions make smokers-turned-vapers like Ms Kligman uneasy.

“If you’re going to sell an adult product, you have to be prepared to secure it,” she said. “But it also seems like they’re making a lot of steps and loops for people like me. They’re taking away a flavour I used for smoking cessation. “

She not only intends to stock up on mango at her corner smoke shop, but is working up a Plan B: “I’ll switch to Juul’s tobacco flavour. I can get around this. Just like the kids will — they can always find a way.”

Nicotine, the chemical in tobacco cigarettes that creates the addictive stranglehold that is so difficult to break, is most likely a signature reason that Juul and other e-cigarettes help former smokers like Kligman quit. In making the switch, smokers can satisfy their nicotine hunger without inhaling the dozens of cancer-causing carcinogens released by a burning cigarette.

Juul in particular may work better than nicotine patches and gum not only because of the amount of nicotine in a Juul pod, but because an e-cigarette’s means of delivery — into the lungs and brain — is more immediate than through skin or saliva. Although studies of e-cigarettes are increasing, they, like the devices themselves, are still in the early stages. The first e-cigarettes arrived in the United States around 2006, but most versions now on the market are far more recent.

And while these products were conceived as smoking alternatives, the Food and Drug Administration has not yet formally approved them as smoking cessation aids, and research is mixed about their effectiveness.

The Centers for Disease Control and Prevention suggest that they can be effective in helping smokers quit “if used as a complete substitute for all cigarettes and other smoked tobacco products.” Like Kligman, about 30 per cent of adult users do exactly that, but nearly 60 per cent use both, the CDC said.

According to a national health survey released earlier this month by the CDC, the number of adult cigarette smokers in the United States dropped to about 34 million last year, while the number of adult e-cigarette users rose to about seven million. But the report didn’t find sufficient evidence to link the two.

Though e-cigarettes are supposedly safer in most respects than combustible cigarettes, they are not benign. Nicotine is not known to cause cancer. It can induce feelings of pleasure and alleviate stress. But in addition to its powerful addictive properties — researchers suggest that the average smoker tries to quit 15 times over a lifetime, with many as much as 30 — nicotine can irritate bronchial pathways and raise heart rates.

According to a 2018 comprehensive evaluation of e-cigarettes by the National Academies of Sciences, Engineering and Medicine, the products are particularly challenging to study because mechanisms and content vary widely. The report said that in addition to nicotine, the long-term effects of the products’ metals, chemicals in the aerosol and flavourings could be problematic.

Now regulators are struggling with how to address competing concerns — weighing the benefits of e-cigarettes for tobacco smokers against the risks for cigarette-naive adolescents.

© 2018 The New York Times