He’s felt angry and stressed.

And for a while, his leg shook uncontrollably.

But 14-year-old Colin Gabriel is determined to give up nicotine.

“It’s very tough,” he said, “but I think, eventually, it could be doable.”

A high school freshman from Bridgewater, Mass., Gabriel was hooked not by traditional cigarettes, but the electronic version preferred by his generation commonly known as e-cigarettes or vapes.

“You kind of build a tolerance for it where you don’t feel the buzz anymore in your head,” he said. “You just want more and more of it to get that buzz.”

What started with a hit of his friend’s vape the summer before eighth grade, he said, progressed to the point where he was using a vaping device made by Juul constantly — in the school bathroom, before he played sports, and, without his parents realizing it, in his bedroom.

Juul users attach a tiny cartridge that can contain as much nicotine as a pack of cigarettes. Until recently, Gabriel said he was going through one-and-a-half Juul cartridges a day.

“I have kids who tell me all they can really think about is nicotine,” said Dr. Sharon Levy, director of the Adolescent Substance Use and Addiction Program at Children’s Hospital in Boston. “A lot of them will have compulsive use. In other words, they really can’t stop.”

The demand for vape-addiction treatment at the hospital has more than doubled in the past year as vaping continues to gain traction among teenagers. The National Youth Tobacco Survey found the number of high school students nationwide who reported vaping went from 3.6 million in 2018 to more than 5 million in 2019 — that’s 27% of high school students.

“The higher dose (of nicotine) results in all kinds of behavioral dysregulation that we have never seen in cigarettes smokers,” said Levy. “Kids who are having difficulty with their attention, with concentration. We’re seeing kids with physical symptoms related to high levels of nicotine, like nausea and vomiting.”

Massachusetts has been at the forefront of an effort to reduce teen vaping. In the wake of an outbreak of vape-related lung illnesses and deaths, Gov. Charlie Baker last fall temporarily banned the sale of all vape products. The governor lifted the ban in December after signing a sweeping new state law designed to make vaping less accessible and attractive to teens.

The law allowed the state’s Public Health Council to enact a series of regulations that will include a 75% tax on vape products beginning in June. Restrictions on retail vape sales are already in effect and include a ban on the sale of flavored vape products and a limit on the amount of nicotine in vape cartridges.

Dr. Michael Siegel, a tobacco control researcher at Boston University’s School of Public Health, gives the new regulations a mixed review. He applauds the move to restrict nicotine levels in vape products, but doubts banning flavors will stop teens from vaping.

“What’s cool to kids is not the flavors. It’s vaping,” said Siegel. “I don’t think many kids even make the choice. They’re getting whatever e-liquids are available from friends or dealers and they’re just vaping whatever’s available.”

Levy, the Children’s Hospital addiction specialist, supports the flavor ban. Without the appeal of fruit and candy flavors, she thinks fewer teens may be tempted to try vaping. Preventing teens from vaping is easier she said than helping them quit. Her program offers teens nicotine replacement medications and counseling, but it’s not clear what will happen in the long-term.

“This is all fairly new,” she said. “Will these kids stay off vaping? Will they ultimately become cigarette smokers, or use some other substance? That’s the unknown question.”

Colin Gabriel relies on nicotine lozenges to stem cravings.

“Sometimes, when I have them in my mouth I’ll suck on my pen to make it feel like I’m vaping again,” he said.

Vaping remains popular among his peers, and he said he refuses frequent offers to buy vape products again. Some kids that used to vape, he said, now smoke traditional cigarettes. The power of nicotine cravings makes staying away from both products a challenge.

“If you haven’t started it yet, don’t try it,” he said, “because the stuff is addictive as anything.”