In case it was too much, Hogan was ready with a vial of naloxone, the overdose-reversal drug.

Grim drug scenes like this play out every day on the streets surrounding San Francisco’s Civic Center—an area that spans the hard-luck sidewalks of the Tenderloin district and the transitional Mid-Market neighborhood, home to the tech titans Twitter and Uber.

The area has become a beachhead for fentanyl, which has killed tens of thousands across the United States and is beginning to make itself felt in California.

The drug, which can shut down breathing in less than a minute, became the leading cause of opioid deaths in the United States in 2016. More and more drug users are seeking it out, craving its powerful high.

Some of those users say they feel a measure of security because many of their peers carry naloxone, which can quickly restore their breathing if they overdose.

Data suggest that in San Francisco, drug users may be reversing as many overdoses as paramedics—or more. In both cases, the numbers have risen sharply in recent years.

Read: America’s health-care system is making the opioid crisis worse

In 2018, San Francisco paramedics administered naloxone to 1,647 people, up from 980 two years earlier, according to numbers from the city’s emergency-response system.

That compares with 1,658 naloxone-induced overdose reversals last year by laypeople, most of them drug users, according to self-reported data from the DOPE Project, a Bay Area overdose-prevention program run by the publicly funded Harm Reduction Coalition. That’s nearly double the 2016 figure.

“People who use drugs are the primary witnesses to overdose,” says Eliza Wheeler, the national overdose-response strategist for the coalition. “So it would make sense that when they are equipped with naloxone, they are much more likely to reverse an overdose.”

The widespread availability of naloxone has radically changed the culture of opioid use on the streets, Hogan said. “In the past, if you OD’d, man, it was like you were really rolling the dice.” Now, he said, people take naloxone for granted.

“I feel like as long as there is Narcan around, the opiates can’t kill you,” says Nick Orlick, 26, referring to one of the brand names for the overdose-reversal drug.

As he huddled in the recess of a building along Mission Street, around the corner from high-rise luxury apartments, Orlick explained that he’d been revived with naloxone 15 times in recent years.

Despite fentanyl’s growing presence in San Francisco and other parts of California, it has not hit the Golden State nearly as hard as the rest of the country.

In 2017, 28,466 people across the United States died from overdoses involving synthetic opioids, which include fentanyl and related compounds, according to data from the Kaiser Family Foundation. California, which represents 12 percent of the country’s population, had 536 of those deaths—less than 2 percent of the total. (Kaiser Health News, which produces California Healthline, is an editorially independent program of the foundation.)