Charles Purnell grew up in Roxbury, the son of a black father and a white mother. His biracial roots made him feel like an outcast — until he turned 15.

"On my 15th birthday, one of my friends came to me and said, 'You’re starting to be a man now,'" Purnell said. "He pulled a syringe out — he didn’t have disposable syringe. It was an old eye dropper, like they used to make 'em. He shot me up with heroin, man. It was a warm feeling. I felt like I belonged. And as soon as I got over the sickness, I went right back out and hung with the same guys."

Purnell’s heroin habit lasted forty years, weathering repeated trips to prison and several failed attempts at recovery. But for the past two years, Purnell has been clean — reconnecting with his wife, his kids, his grandkids, and now, a great-grandchild. Purnell credits the medication Suboxone, which he calls a "miracle drug."

"It made me feel normal — whatever normal is after 40 years shooting dope," he said. "I found a new life, put it like that."

Suboxone’s ingredients include the anti-overdose drug Naloxone, also known as Narcan — and buprenorphine, which activates the same pleasure receptor as heroin, but with a more muted effect.

"When you shoot dope, you automatically get like a warm feeling that goes through your body and your blood," Purnell said. "It’s just like — oh, close your eyes, float away wherever want to go. Suboxone — remember the cartoon Popeye? How he used to eat spinach, open a can, eat the spinach, he’d go boom boom boom? That’s how Suboxone makes you feel. It gives you an energy boost, then you come down to normal. And that’s it."

Suboxone has its critics. They say it’s sold on the black market — that some doctors treat it as a cash cow — and that it replaces one addiction with another. But Colleen Labelle, director of Boston Medical Center's primary-care addiction clinic — where Purnell gets his treatment — says those complaints miss the point.

"People are dying in ridiculous numbers," she said. "I mean, we’re losing 120 people a day in this country. That’s an outrage!"

Labelle welcomes more oversight of Suboxone prescribers — but she also wants more doctors to embrace the drug. Unlike methadone, Suboxone can be prescribed in ordinary clinical settings. When it is, she says, patients get vital treatment — and some key moral support.

"You get your physical exam and you get your flu shot, and you’re getting your medication to treat your opioid dependence all in one place," she said. "It takes the stigma away.

Labelle says she’ll help any patient who wants to get off Suboxone. But she doesn’t think everyone should.

"This is a chronic relapsing disease, and people die when they’re not in care," she said. "If somebody wants to be on it the rest of their life, they should be on it."

For his part, Purnell has dropped from 16 milligrams of Suboxone a day down to four. The prospect of quitting altogether frightens him.

"If they just cut me off right now, I’d probably be scared to death," he said.

But when I ask if he’s addicted to Suboxone, he says it doesn’t matter.

"I just know I don’t want to do heroin no more, and Suboxone is keeping me doing," Purnell said. "If it’s not broke, I don’t want fix anything. Don’t wanna go jail, and I don’t want to die. If I go home, my kids run and grab my legs now. I’m living life, man."