HONG KONG — Hong Kong banned CBD as a "dangerous drug" and imposed harsh penalties for its possession on Wednesday, forcing fledging businesses to shut down or revamp.

Supporters say CBD, or cannabidiol, derived from the cannabis plant, can help relieve stress and inflammation without getting its users high, unlike its more famous cousin THC, the psychoactive ingredient of marijuana which has long been illegal in Hong Kong. CBD was once legal in the city, and cafes and shops selling CBD-infused products were popular among young people.

But all that has changed with the prohibition, which took effect Wednesday but had been announced by the government last year. CBD-related businesses have closed down while others have struggled to remodel their businesses. Consumers dumped what they saw as a cure for their ailments into special collection boxes set up around the city.

The new rule reflects a zero-tolerance policy toward dangerous drugs in Hong Kong, a semi-autonomous southern Chinese business hub, as well as in mainland China, where CBD was banned in 2022.

The city maintains several categories of "dangerous drugs," which include "hard drugs" such as heroin and cocaine.

In explaining the policy change, the Hong Kong government cited the difficulty of isolating pure CBD from cannabis, the possibility of contamination with THC during the production process and the relative ease by which CBD can be converted to THC.

Customs authorities vowed last week to do more to educate residents to help them understand that CBD is prohibited in Hong Kong even though it is legal elsewhere.

Starting Wednesday, possession of CBD can result in up to seven years in jail and a 1 million Hong Kong dollar ($128,000) fine. Those convicted of importing, exporting or producing the substance can face up to life in prison and a 5 million Hong Kong dollar ($638,000) fine.

Some users said the ban shows the international financial hub is going backward.

"It's just looking less like an international city," said Jennifer Lo, the owner of CBD Bakery, who started selling CBD-infused cheesecakes, cookies and drinks in 2021.

Her business largely dried up even before the ban took effect, she said.

"Rumors of the ban affected how I do business," she said. "Some platforms just took me offline without telling me. And then it was not as easy to get space at markets."

To comply with the ban, Lo dumped all her remaining stock, including dozens of cookies, and said she would have to rebrand her business.

Some other vendors, including the city's first CBD cafe that opened in 2020, shut down.

Karena Tsoi, who used CBD skincare products for two years to treat her eczema, said she will have to find an alternative treatment.

"It's troublesome," she said. "The government doesn't have to regulate like this."

Most Asian nations have strict drug laws with harsh penalties with the exception of Thailand, which made marijuana legal to cultivate and possess last year.

Elsewhere, the debate over CBD continues.

The U.S. Food and Drug Administration said last week that there is not enough evidence about CBD to confirm that it's safe for consumption in foods or as a dietary supplement. It called on Congress to create new rules for the growing market.

Marijuana-derived products have become increasingly popular in lotions, tinctures and foods, while their legal status has been murky in the U.S., where several states have legalized or decriminalized substances that remain illegal federally.