At first, it sounds crazy: fighting heroin abuse by giving addicts an open-ended, high-quality and free supply of the drug.

But a doctor testifying Wednesday on Capitol Hill says doing so can improve addicts' mental and physical health while reducing government spending and sparing the public from drug-related crime.

“It’s an evidence-based treatment option when the standard treatments – methadone, suboxone, buprenorphine – have not worked,“ says Dr. Scott MacDonald, lead physician at Providence Health Care’s Crosstown Clinic in Vancouver, Canada.

“This attracts people into care, and it’s safe and we have evidence to support its use,” MacDonald says. “We need every tool in the toolkit to fight this epidemic.”

The Crosstown Clinic currently is the only place in Canada where long-time heroin addicts legally get heroin (diacetylmorphine) in treatment called heroin-assisted therapy. Though radical by U.S. standards, the treatment already is integrated into the health systems of European countries including the Netherlands , Denmark and Switzerland .

The idea is that clean heroin injected under medical supervision is far less likely to kill treatment-resistant addicts, and that by reducing addicts' need to beg and steal their lives become more orderly, even if they remain active drug users.

Several clinic patients spoke with U.S. News and say injecting free and clean medical heroin under supervision and with support from social services changed their lives for the better, though none have yet escaped the grasp of their long-term addictions.

Dianne Tobin, 54, says she used heroin for decades and sought to join Canadian research efforts into heroin-assisted therapy because of fear that street heroin cut with pig de-wormer and other unknown substances would kill her.

“The heroin got terrible and laced with all kinds of stuff and that’s why I didn’t want to do it anymore,” she says.

Two major studies in Canada have explored the potential of heroin-assisted therapy and Tobin was part of both.

First, the NAOMI study, which ran from 2005-2008, contrasted medical heroin favorably against methadone among 251 long-term addicts. Then, the follow-up SALOME study, with 202 participants, each an addict for at least five years with failed past treatments, contrasted medical heroin against injectible use of the painkiller hydromorphone.

MacDonald says SALOME found improved quality of life among patients, 80 percent of whom stuck with the program. Medical heroin and hydromorphone appeared equally effective, though user preference varied. Following a court battle, patients of the completed study were allowed to resume using medical heroin in late 2014.

Tobin says she used medical heroin for a while, then after lowering her dose transitioned to injectable hydromorphone for a few months. But at that point she had no veins left into which she could inject drugs, causing her to “muscle it” by shooting into muscles instead.

“I was getting black and blue and it was stinging and I wasn’t going to be walking around with black and blue arms all the time,” she says.

So Tobin, who says she never went to a rehab but first took methadone nearly 40 years ago, switched to oral hydromorphone once a day. And recently she says she stopped taking methadone for the first time in 25 years and sees the novel injectable treatment options as offering a way to step away from addiction.

“Within the next year I’m going to be off it totally,” she says. Unlike many heroin addicts, Tobin is a former small business owner – of a bakery and stucco business – and says she’s been able to re-establish her footing leading a women’s support group.

If heroin-assisted therapy was legal throughout North America there would be fewer heroin addicts and “there would be a lot less crime and a lot less overdoses,” she says.

But other patients have a more complicated trajectory and no near-term plans to quit heroin.

A 51-year-old man who asked to be identified only as “Spike” says he still injects medical-grade heroin under medical supervision three times a day.

“For me, I will always have a need for pain management. That will be an ongoing issue for the rest of my life,” he says. “My long-range plans are, I’m hopeful that in Canada we’re entitled to keep getting legally prescribed heroin.”

Spike says he used opioids when he was younger, but became seriously addicted after being prescribed legal painkillers following an accident in 2007. Before SALOME began treating patients in January 2012, he was run over by a garbage truck and broke bones in his spine and legs. He had a minor stroke days after beginning the SALOME study.

“I was tired, I couldn’t do it any more – I wanted to change where I was headed because I was definitely heading to prison or death,” he says. “SALOME came just in time.”

He does not have plans to move off of heroin or lower his dose. Injectable hydromorphone, he says, wasn’t as effective at numbing pain and not as long-acting. He says he won’t move from medical heroin to hydromorphone unless he’s forced.

But he says his quality of life has stabilized and the social harm of his addiction decreased. He works part time selling magazines and hopes to find full-time work.

“I don’t have to spend my life wielding, dealing and stealing anymore,” he says. “I’m not a criminal for healing my pain anymore.”

Spike says he sees others in the program with success moving slowly away from opioids, saying “it levels people out and then they are able to make healthy choices because they are not chasing their own tail all day.”

Another program participant, a 51-year-old named Lori, who asked that her last name be withheld, says she has no immediate plans to stop using medical heroin, which she injects twice a day, though she hopes ultimately to try the medication Suboxone if her health insurance provider allows it. She says if she was on public assistance the drug would be covered, but her husband works.

Lori says she first tried heroin when she was 35 years old after only occasionally using marijuana in her youth and cocaine a few times as a young adult. She says she slowly went from a condo owner with a successful career that included 10 years of behind-the-scenes TV station work and nearly as long in marketing to unemployed, pawning her wedding ring and struggling for ways to sneak drug money from her husband.

“It’s so stupid. I was really depressed and I tried it, and every so often this guy would say can I borrow $10 for heroin? And I’d say, ‘OK, and OK I’ll use some,’ and within two years I was using heroin every day” she recalls. “I was curious, quite honestly, and really depressed.”

She says rehabs and detoxes did not work for her and now she doesn’t have the stress of finding drugs or the sickness that came when she could not. “It’s orderly, it’s stable,” she says, describing herself as someone who doesn’t look at all like a drug addict.

Unlike Spike, she says hydromorphone seems to be effective for longer than medical heroin. And she says there’s a cleaner feel from the legal painkiller, too. But she prefers the medical heroin.

“With the medical heroin, I’m sick in the morning. I have a runny nose and can feel a little drug sickness, but with the hydromorphone I didn’t feel that,” she says. “I prefer the feeling of the heroin. It’s more of a heroin feeling. The hydromorphone doesn’t feel quite like heroin does. The medical heroin is more like regular heroin, but it’s not like regular heroin.”

Lori says with street heroin "you’d get a nice warm feeling like a warm blanket coming over you,” a feeling she does not get from medical-quality heroin. She says forcefully that anyone curious about heroin should just stay away and that she naively didn’t realize experimentation would turn her life upside down.

On Wednesday, members of the Senate Committee on Homeland Security and Governmental Affairs will hear from Dr. MacDonald and a fellow advocate for heroin-assisted therapy, Ethan Nadelmann, executive director of the Drug Policy Alliance, a large advocacy group. Two other witnesses include David Murray, senior fellow at the conservative Hudson Institute, and Arlington, Massachusetts, Police Chief Frederick Ryan.

MacDonald says medical heroin, which for his clinic comes from Switzerland, is sterile and of a predictable strength, unlike street heroin, and that although continued heroin addiction is not ideal, it’s the best and most realistic option for some people.

Of more than 80,000 injections during the SALOME study among its 202 patients, injection-supervising nurses had to intervene 11 times in overdoses, he says, in each case preventing patient death.

MacDonald says that injectable hydromorphone probably is a more realistic near-term policy change in the U.S., but points to Denmark's abrupt embrace of heroin-assisted therapy as evidence of what can happen if there's political will to make a drastic change.

The matter has begun to attract some attention in the U.S., but not much, as heroin remains an impossible to prescribe and difficult to research Schedule I drug. Maryland Democratic Delegate Dan Morhaim, an emergency room doctor, floated the idea last year as a way to reduce the social burden of drug-related crime, but it went nowhere.

Still, MacDonald has his sales pitch ready.