FDA regulators said Thursday that Juul’s studies show its e-cigarettes are less harmful for adult smokers, who can benefit from switching completely to vaping.

The FDA decision applies to both tobacco- and menthol-flavored versions of the reusable product, which works with nicotine-filled cartridges sold in two different strengths. Juul previously discontinued several fruit and candy flavors that helped drive its popularity but were favored by teens.

Juul will be one of only two U.S. companies authorized to sell menthol-flavored vapes, which many adults prefer to tobacco flavor.

“This is an important milestone for the company and I think we made a scientifically sound case for the role that menthol can play in e-vapor,” Juul CEO K.C. Crosthwaite told The Associated Press.

Parents, politicians and anti-tobacco groups are certain to oppose FDA’s decision. They have argued for years that Juul products should be permanently banned due to their role in triggering a yearslong spike in underage vaping.

“It is a big step in the wrong direction to authorize sales of the product that was responsible for this public health crisis in the first place,” said Yolonda Richardson, CEO of the Campaign for Tobacco-Free Kids in a statement.

Juul was once valued at over $13 billion and its small, sleek e-cigarettes revolutionized the image and technology of the vaping industry. But the company has since been forced to slash hundreds of jobs and pay billions to settle lawsuits over its role in the rise of youth vaping.

The FDA had ordered the company to remove its products from the market in June 2022. But then the agency abruptly reversed course days later and agreed to reopen its scientific review of Juul’s application after the company pushed back in court.

Juul said that regulators had overlooked thousands of pages of scientific data critical to its submission.

Thursday’s announcement is not an approval or endorsement, and the FDA reiterated that people who do not smoke should not use Juul or any other e-cigarettes. The FDA determination indicates that smokers who switch completely to Juul can reduce their exposure to deadly carcinogens and other chemicals found in traditional cigarettes.

The FDA decision applies to Juul’s original system, which is now roughly a decade old. Crosthwaite said the company hopes to win authorization for its next-generation device and is also considering applying to FDA for more flavors.

“It’s critically important that American adults who use tobacco have regulated options,” Crosthwaite said.

In recent years, the FDA has authorized a handful of e-cigarettes to help adult smokers cut back on cigarettes. Juul’s main competitors, Vuse and Njoy, each previously received FDA permission to remain on the market. Njoy sells the only other menthol-flavored e-cigarettes authorized by FDA.

To meet FDA requirements, companies must show that their products benefit public health. In practice, that means proving that adult smokers who use them are likely to quit or reduce their smoking, while teens are unlikely to get hooked on them.

The brainchild of two Stanford University students, Juul launched in 2015 and within two years rocketed to the top of the vaping market.

Juul quickly outpaced older brands with its high-nicotine, fruity-flavored cartridges, sold in mango, mint and creme brulé. The company’s small, discrete devices provided a more potent, user-friendly alternative to older, bulkier devices.

But the company’s rise was fueled by underage use, and e-cigarettes quickly became ubiquitous in U.S. schools. In 2019, the company was pressured into halting all advertising and eliminating most of its flavors, leaving only tobacco and menthol-flavored options.

By then the company was already the target of multiple investigations and lawsuits by federal, state and local officials as well as class action attorneys.

In 2022, the company paid $1.7 billion to settle thousands of lawsuits brought by families of Juul users, school districts, city governments and Native American tribes. The company separately agreed to pay $1.1 billion to settle lawsuits or investigations from most U.S. states.

Juul is no longer the top-selling e-cigarette brand and now trails Vuse, which is sold by tobacco giant Reynolds American, which also makes Camel and Newport cigarettes.

Teens have shifted away from Juul amid a wider drop in vaping, according to the latest federal figures. The FDA reported last year that teen vaping dropped to a 10-year low, after stepped up enforcement against unauthorized brands imported from China, such as Elf Bar.

Unlike Juul, disposable e-cigarettes like Elf Bar still come in fruit and candy flavors, despite efforts by regulators to block their use.