VANCOUVER, British Columbia — The place where Chris gets his fentanyl is bright and airy, all blond wood and exposed brick. The staff is friendly and knowledgeable about the potency of the pills he can crush, cook and inject.

Soft pop music played, and an attendant spritzed a bit of Covid-cautious spray on his seat before he settled into a booth on a recent afternoon with a couple of red-and-yellow pills, a tourniquet, a tiny candle and a lighter.

“The best thing about this is the guarantee: I can come in here four times a day and get it,” Chris said. He no longer spends all of his waking hours in a frantic scrabble of panhandling and “other stuff” to scrape up the cash to pay a dealer. He won’t get arrested — and he won’t overdose and die using a drug that is not what it is sold as.

This fentanyl dispensary is legal, and Canada’s public health system finances it.

It is the latest and perhaps most radical step in a city that has consistently been at the leading edge of experiments in “harm reduction,” an approach to reducing deaths and severe illness from illicit drugs by making the drugs safer for people who use them. Harm reduction, even in basic forms such as the distribution of clean needles, remains deeply controversial in the United States, although the concept has been gaining fitful support as overdoses rise, including from the Biden administration.

But the breadth of Vancouver’s services and interventions is almost unimaginable in the United States, less than an hour’s drive to the south. Supervised injection sites and biometric machines that dispense prescription hydromorphone dot the city center; naloxone kits, which reverse overdoses, are available free in every pharmacy; last year, a big downtown hospital opened a safer-use site next to the cafeteria, to keep patients who are drug users from leaving in order to stave off withdrawal.

And since April, Chris, a wiry, soft-spoken 30-year-old who wanted to be identified by only his first name to protect his privacy, has received pharmaceutical-grade fentanyl through the dispensary, which sells to those who can pay and provides free drugs through the program’s operational budget to those who cannot.

The new program aims to provide a safer alternative to the fentanyl available on the streets, where the supply is increasingly lethal and is responsible for most of the overdose epidemic that was declared a public health emergency here six years ago.

Dr. Christy Sutherland, a board-certified addiction medicine specialist who set up the program, said its goal was, first, to keep people from dying, and, second, to help bring stability to their lives so that they may think about what they might want to change.

Chris started using pills recreationally in his teens, then moved to heroin. But the heroin supply in Vancouver was taken over about a decade ago by fentanyl, an opioid that is 50 to 100 times as potent and thus far more profitable for the cartels that sell it.

Overdose deaths have surged in British Columbia since the start of the Covid pandemic, as they have across the rest of North America. Some 2,200 people died of overdoses in the province last year, among the 115,000 lives lost to drugs in Canada and the United States during that time. The mounting toll has spurred communities to search for new solutions, and this city has tried more of them, faster, than anywhere else.

Vancouver’s experiments have government support and are paid for by the public health system on the expectation that they will save not only lives but also taxpayer dollars — in reduced emergency services and hospitalizations.

But there is concern from both the general public and some addiction medicine specialists here. They say that the latest efforts go too far, diverting resources from proven treatments to experiments that have not been shown to reduce drug use or save lives, and risking an increase in the numbers of both users and deaths. Supplying drugs is for criminals, not health clinics, they say.

“These are highly potent substances that produce quite a bit of harm,” said Dr. Launette Rieb, an addiction medicine physician who has worked for decades with drug users in Vancouver. “When access increases, costs go down and perception of risk goes down.”

Evidence of the effectiveness of these interventions in saving lives is limited, she said.

A clinical trial in Vancouver found that providing injectable heroin to patients who had not responded to other forms of treatment helped them reduce their use, stay tied to health care and improve their quality of life, compared with users who were given methadone. Another found a similar benefit from prescribed hydromorphone. Research on the fentanyl program has just begun but will track whether it shows a similar benefit, which could justify expanding it.

In June, British Columbia received an exemption from federal drug laws that will allow the province to decriminalize individual possession of up to 2.5 grams of hard drugs, starting early next year. The police will no longer confiscate small amounts of drugs, and no user will be required to seek treatment to avoid arrest, but drug trafficking and production will still be crimes.

The decriminalization is a significant step beyond Canada’s legalization of cannabis use in 2018. Proponents say it should be a first move toward a regulated government supply of all drugs as the best way to respond to growing toxicity, which is the immediate cause of overdose deaths.

Fentanyl has largely displaced heroin and the opioid painkillers Dilaudid and OxyContin as the illicit drug most used in Vancouver, a shift underway throughout North America. It is also often cut into other drugs, including non-opioid prescription medications such as the attention deficit disorder medicine Adderall, which is sold on the street as a stimulant. Its potency and users’ inability to know what they are buying or how strong it will be have led to the huge surge in overdoses.

Dr. Sutherland, an effervescent, fast-talking 41-year-old, is the medical director of a social service agency called the PHS Community Services Society. It serves the Downtown Eastside, a neighborhood that has long been the site of intense drug use and advocacy by and for drug users. It was home to North America’s first needle exchange, first supervised injection site and first prescription heroin program.

Dr. Sutherland said she was tired of responding to overdoses on the sidewalk outside her clinic, knowing that if she could go back in time 10 minutes and give people safer drugs, she wouldn’t be trying to save their lives.

She began her medical practice working with homeless people. She said that those patients, and others living on the social margins, shifted her thinking on drug use from “Drugs are bad and are outlawed to keep people safe” to seeing addiction as a disease that she could help people overcome. Now she takes it one step further with a view that is gaining traction in British Columbia: There will always be people who use drugs, so all drugs — not just alcohol and tobacco — should be regulated by the government and sold in a controlled, legal market.

“Treatment and recovery is not the answer to a toxic drug supply. Getting rid of the toxic drug or giving alternatives to the toxic drug supply is,” she said. “You can start there and talk about treatment and recovery down the road a bit.”

It’s not realistic to think that people will abstain from substances, she said, and so the role of the state should be to keep substances safe and take access out of the hands of organized crime.

Back in 2010, Dr. Sutherland began prescribing what is called opiate agonist therapy, or medication-assisted treatment, to patients who were using street drugs. That includes methadone, Suboxone and Kadian, long-acting opioids that satiate the craving for an opiate without providing the high. She helped stabilize many users and connect them with treatment to stop using altogether. But some intended to keep using, and the therapy failed for others, and Dr. Sutherland concluded that what those users needed was safer drugs.

So she started to provide a replacement for the street drugs, first Dilaudid, then fentanyl patches, and, now, the fentanyl capsules. Her project purchases the fentanyl from a pharmaceutical manufacturer, and a local pharmacy compounds it, with dextrose and caffeine as buffers. The pills are sold at $10 a hit, priced to match the street rate exactly.

Dr. Sutherland writes a prescription for the drug, and patients buy it; if they can’t pay, the program covers the cost.

When nurses enroll new participants in the program, they increase the dose over days to find exactly what the patients need to replace what they use on the street. Participants use the drugs under supervision at first, to make sure they have the amount they need to avoid withdrawal (and no more, so that there is no risk they will sell excess on the street). Then, they can take the drugs off-site to use.

Chris has been a daily user of illicit drugs since he was a teenager. He receives 30,000 micrograms of fentanyl at the dispensary each day. That is vastly more than would kill a nonuser — a doctor would typically prescribe about 50 micrograms temporarily to manage pain — but, after years of use, it is what Chris needs to feel a quick rush of euphoria and prevent withdrawal. He said he hoped to return to working soon and then would start buying from the program, the way he would patronize a liquor store.

Dr. Sutherland expects that patients such as Chris may gradually reduce the amount they use, because they’re not worried about how they will score the next hit to keep the agony of withdrawal — being “dope sick” — at bay.

Lisa James personifies the anticipated benefit of programs like this. Ms. James, who is 53, spent 18 years addicted to heroin. For the first eight, every day began the same grim cycle: She’d go out in the morning and steal from stores, then pass the merchandise to her boyfriend, who would resell it and use the money to buy heroin. He’d bring it home, where she was waiting anxiously, already nauseated and twitchy with dope sickness.

“Doctors would all say the same thing, ‘Go to detox and go to meetings,’” Ms. James said. “And when you’re that far down in it, that’s like a lifetime away. You can’t even imagine getting through two days, never mind going into detox.”

Ms. James failed repeatedly at treatment. What turned her life around wasn’t quitting heroin but rather receiving pure medical-grade heroin from the Crosstown Clinic, which is run by the British Columbia health care system and provides the drug free of charge. When she was taken on as a client there a decade ago, Ms. James stopped stealing, stopped hustling and was able to set down the constant terror of wondering if she would be able to buy the next hit. She got a job, and the Crosstown staff helped her find an airy apartment in the suburbs to share with her daughter.

She may one day stop using heroin, she said, but she doesn’t need to decide that now. “With this program, even if I have to keep using something to stay off street drugs, I’m willing to do that,” she said. “I feel really lucky to live here.”

But critics of this and other safer-supply initiatives reject this idea, arguing that opioid use disorder is a brain disease and one that can be effectively treated. Dr. Annabel Mead, a Vancouver addiction specialist, said her initial hesitancy about safer-supply programs — should a doctor whose first rule is “do no harm” give out highly addictive drugs? — had been reinforced by the growing number of children she sees at B.C. Children’s Hospital who have overdosed.

She said that a hydromorphone dispensing program, set up to try to help people with addictions to isolate during Covid lockdowns, was partly to blame for a surge in teen use: Drug users prescribed Dilaudid are selling pills to young people and using the money to buy fentanyl that has the potency they are used to, she said.

In the meantime, she added, the province is spending too little on abstinence-based treatment; there is a nine-month waiting list for the main residential women’s treatment program. Many skeptics of safer supply here argue that treatment that aims to help people stop using is being shortchanged, but British Columbia’s 2021 budget designated $330 million for new treatment and recovery services for substance use, which was an increase. The total far outweighs the spending on safer supply.

Some people say the steps in Vancouver don’t go far enough. The Crosstown Clinic has 116 people on its prescription heroin and Dilaudid programs. Dr. Sutherland thinks she can supply about 100 people with fentanyl, for now. Several hundred people are also receiving safer drugs through their pharmacy under prescribing guidelines that the provincial government loosened in the first days of the pandemic, when supervised injection sites were closed.

But there are more than 85,000 people at risk of overdose in British Columbia every day, from daily users on the street to occasional users who don’t live anywhere near a supervised injection site.

“Harm-reduction services are like a candle for lighting something, a tiny intervention into this monstrous toxic cesspool of fentanyl and its analogues,” said Donald MacPherson, director of the Canadian Drug Policy Coalition and professor at Simon Fraser University.

He added, “We need to do something big.” The rate of death demands much more sweeping intervention, he said. “The incremental is no good. No more pilot projects.”

Dr. Bonnie Henry, British Columbia’s health officer, said there was little choice but to move incrementally.

“Incrementalism is the only way it’s going to work,” she said. “We have to evaluate it, and the evaluating has to be done independently by somebody who’s not committed to seeing it fail or to seeing it succeed.”

At the same time, she is part of a community that includes government, researchers, doctors and drug users, all trying to envision what a new, safe, regulated market could look like. “People don’t deserve to die because of the toxicity of the street supply,” she said. “So how else can we help?”