A JUUL vape Brianna Soukup | Portland Press Herald | Getty Images

Juul has prided itself on its independence from Big Tobacco. It may not be able to much longer. The e-cigarette maker is in talks to sell a stake of the company to Altria, a person familiar with the matter tells CNBC. Earlier this fall, Juul paused efforts to raise money from private investors because of regulatory uncertainty, people familiar with the matter say. The fundraise would have valued Juul at more than $20 billion, these people said. The change of course highlights the existential crisis in which Juul finds itself. Its fruity flavors, questionable past marketing and explosive popularity among teenagers have invited critics to compare it to Big Tobacco and the days of the Marlboro Man and Joe Camel.

Juul designed its devices to look completely different from cigarettes. The company has used its autonomy — and its purported purpose of eliminating conventional cigarettes — to brush off those comments. That wasn't enough to prevent attention from the U.S. Food and Drug Administration. Today, Juul is able to market itself as an enemy of Big Tobacco, simply trying "to improve the lives of the world's 1 billion adult smokers." That will become much harder to do if it sells part of itself to Altria, the maker of top-selling cigarette Marlboro. However, in teaming up with Altria, Juul would gain regulatory expertise to help it manage the tricky waters that are becoming even choppier as the agency cracks down on rising rates of teen vaping.

Surging sales, growing scrutiny

Over the summer, Juul closed a $1.25 billion round that valued the company at $16 billion after a year of explosive growth for the company. At that point, Juul's dollar sales had skyrocketed 783 percent in the 52 weeks ended June 16, reaching $942.6 million, according to a Wells Fargo analysis of Nielsen data. The e-cigarette category as a whole grew 97 percent to $1.96 billion in the same period. Juul now represents more than 75 percent of the e-cigarette market, according to the Nielsen numbers. But Juul faced a growing and glaring problem: Anecdotal reports suggested many of its customers were teens. Federal data later proved a surge in teen e-cigarette use was underway. All the while, Juul maintained its argument it was a health-focused company that wanted to help adults switch. And it wasn't associated with any tobacco companies. "We're the No. 1 e-cigarette in the United States," Juul's Chief Administrative Officer Ashley Gould told The New York Times in April. "And we're not a big tobacco company. We're an independent company." Weeks after the story, in a rare move, the FDA issued a 904(b) letter requesting a slew of company materials, including marketing documents and research on whether certain products' design features, ingredients or specifications appeal to different age groups. In September, the FDA went even further, declaring teen e-cigarette use an epidemic and placing the blame on Juul and four other brands, including Altria's MarkTen. Commissioner Scott Gottlieb ordered the companies to come up with a plan to reverse these trends. The same month, federal authorities showed up at Juul's San Francisco headquarters unannounced, seeking more information on the company's sales marketing practices. They seized more than a thousand pages of documents. Juul CEO Kevin Burns in a statement said the company walked regulators through "every part" of its business, including its marketing practices and age-verification tools used on its online shop. As the FDA scrutinized Juul and debated its next steps, the outcry grew even louder. Federal data proved parents and teachers weren't wrong. In just one year, the number of high school students who used e-cigarettes increased 78 percent, equating to 20.8 percent of high school students. It could not be determined how much of Juul's business is teens, but some estimate it is significant. The FDA regulation could therefore represent pressure to Juul's business. Meantime, Juul is spending millions of dollars to combat underage use and conduct clinical studies in order to prepare for an application it will eventually need to file with the FDA. Weeks before the FDA announced how it would try to curb youth use, Altria in October said it would remove its MarkTen pod-based products and will stop selling all flavors except for menthol or tobacco in its cig-a-like products until the FDA reviews and approves them. Juul said it suspended sales of fruity flavors in retail stores while continuing to sell these flavors on its age-verified website. Two days later, the FDA said it would restrict where these flavors can be sold, limiting them to age-verified stores such as tobacco and vape shops.

A fresh batch of skepticism