It’s got a lot of critics and unanswered questions, but a proposal adopted by the Massachusetts Medical Society in April to advocate for a pilot supervised injection facility for illicit drug users is gaining momentum.

Two weeks ago, Boston city councilors called for public hearings on supervised injection sites. And a bill filed by state Sen. William N. Brownsberger, D-Belmont, is awaiting a hearing date in the Joint Committee on Mental Health, Substance Abuse and Recovery. The bill, S. 1081, is co-sponsored by local Sens. James B. Eldridge, D-Acton, and Anne M. Gobi, D-Spencer.

The concept, which has been in practice in Vancouver, Canada, for more than a decade, as well as in Australia and Europe, is to have a safe, clean space where persons who inject themselves with illicit drugs can use their own drugs. The facility would have medical staff on hand who could intervene with naloxone, the overdose-reversing drug in Narcan, and other first aid in case of emergency.

More importantly, supervised injection facilities can help get people with substance use disorders into treatment, according to Dr. Dennis M. Dimitri, vice chairman of the Department of Family Medicine and Community Health at UMass Memorial Medical Center and a clinical associate professor at University of Massachusetts Medical School.

Dr. Dimitri is the chairman of the medical society’s Task Force on Opioid Therapy and Physician Communication, and a past president of the society.

“If we can make it safer for them and more likely for them to live, they’re more likely to get into treatment,” Dr. Dimitri said.

In a perfect world, nobody would inject illicit drugs, Dr. Dimitri agreed. But supervised injection facilities reflected “the public health approach of harm reduction.”

More than 2,000 people in Massachusetts died from an opioid-related overdose in 2016, state officials reported.

He said the concept is similar to sterile needle exchange programs to reduce the spread of HIV/AIDS, which despite initial opposition have been shown to be effective. Injection facilities, which offer clean needles, have also been shown to reduce the spread of HIV/AIDS.

The proposal was brought forward to the medical society’s House of Delegates over a year ago by a group of medical students, Dr. Dimitri said. Over the past year the society has been researching it and adopted at its annual meeting in Boston on April 29 a policy advocating for a pilot supervised injection site, under the oversight of the state Department of Public Health.

Looking at the experience from Vancouver, he said, there was “pretty convincing evidence” that the facilities were an effective tool in fighting opioid addiction and deaths.

Specifically, there was a 35 percent reduction in overdose mortality. Supervised injection facility use was also associated with an increase in referral to addiction treatment, including a 30 percent increase in the rate of detoxification use and an increase in the use of medication-assisted treatment.

Their research found, too, that the feared “nuisance factor” of bringing more drug-related disturbances to the area didn’t materialize.

“This is a tool. This is not a panacea,” he said.

Supervised injection facilities were particularly helpful in reaching people who are homeless, unemployed and generally less connected with the medical system.

While the medical society endorsed the concept, a lot of details would need to be addressed by a study group, according to Dr. Dimitri. First, federal and state laws outlaw being in the presence of heroin. Liability for the supervising nurses and doctors would also be a concern, since malpractice insurance wouldn’t cover those services.

In January, Seattle became the first U.S. city to approve supervised injection sites. Besides Boston, New York City and San Francisco are among the locales exploring the option. Legislation is pending in Maine as well.

“The political drumbeat is beginning to get a bit louder on this issue,” Dr. Dimitri said.

State Sen. Jennifer L. Flanagan, a Leominster Democrat who chairs the committee to which Mr. Brownsberger’s bill, which calls for a “safer drug consumption program,” was referred, has reservations.

“As chair of the committee, I need to know more about it,” she said. “On the surface, I’m not supportive of this initiative.”

Ms. Flanagan said she was uncomfortable putting state money into it, and had questions about where a site would be placed, its impact on crime and other issues.

She plans to travel to Vancouver to study that city’s experience.

“I’ve kept an open mind. I’ve certainly done the academic research. I just want to see it in practice,” she said.

While there is no injection site operating nearby, Boston Health Care for the Homeless Program opened a site last year where people who had already ingested drugs could ride out their high under medical supervision.

The Supportive Place for Observation and Treatment, or SPOT, is a 10-chair unit in a former conference room at the program's South End location.

“It’s very heavily utilized,” said Dr. Jessica Gaeta, chief medical officer. So far there have been 3,800 encounters with 500 people, an average of seven or eight per person.

“These patients are extremely high risk,” Dr. Gaeta said. More than half of those who come in had overdosed in the prior month.

Staff have learned a lot about the opioid epidemic and emerging trends from talking with people who come to SPOT, according to Dr. Gaeta. Visitors don’t have to give their names, don’t pay for services and are often more willing to speak openly about their drug use.

One alarming trend is a cocktail of five drugs being used at a time. This mixture includes heroin, the benzodiazepine Klonopin, an anti-epileptic medicine called Neurontin, blood-pressure medication Clonodine and the antihistamine and anti-nausea drug Phenergan.

Instead of getting high right after injection, which is what happens with opioids alone, the high from the mixture might not peak for two or three hours, according to Dr. Gaeta. The overdoses are more complex, with heart rates down to as low as 30 even before breathing slows.

Medical staff monitor visitors and intervene when needed with oxygen, intravenous fluids and naloxone.

Dr. Gaeta told The Washington Post in January that about 10 percent of their visitors have entered treatment programs.

She emphasized that injections are illegal and Boston Health Care for the Homeless Program was not operating, or seeking to operate, a supervised injection facility.

But she said, “If the laws are changed and the state or city asks us to operate one, we would.”

Holden resident Annie Parkinson, regional coordinator for Central and Western Massachusetts for the Massachusetts Organization for Addiction Recovery, said the approach needed to be studied because much is unknown.

"I think it's a very hard concept for people," Ms. Parkinson said. While some say offering a safe place to inject drugs amounts to enabling people with addiction, "you don't think candy stores are enabling diabetics."

Ms. Parkinson said the connections drug users would make with medical staff at the sites, during a critically vulnerable time, might help them into recovery.

"I think we have to be very creative going forward," she said. "We'll always be out-thought by the drug dealers and the cartels. We need more creative thinking."

Until the Legislature acts on the issue, state and local officials aren’t moving toward this model any time soon.

A state Department of Public Health spokesperson said in an email: “Fighting the opioid epidemic is a public health priority of the Baker-Polito Administration…. The administration's evidence-based efforts to build a strong foundation of prevention, intervention, treatment and recovery will continue and expand to fight this epidemic.”

“We have no plans to pursue that idea at this time,” John F. Hill, communications specialist for the city of Worcester, wrote in an email. “Worcester has made many strides dealing with the opioid epidemic, including outfitting every public safety official with Narcan, training other city staff members and members of the public on Narcan use, implementing training for local physicians on safe prescription practices and starting a clean needle exchange program through AIDS Project Worcester. We will continue to fight the opioid crisis through education and advocating for better access to treatment.”

Worcester District Attorney Joseph D. Early Jr. isn’t on board, either.

“We are more focused on treatment and not enabling people to continue to use illegal drugs,” he said. “We’re in the business of treatment and rehabilitation. I’d rather see someone get a bed.”

Mr. Early said he supported addiction treatment with medications including Suboxone, methadone or Vivitrol, combined with counseling. But he feared providing opportunities for opioid injection would lead to more deaths.

“Is this really where we want to be going?” he asked.