Peer 'Injection Doctors' Cut Risky Syringe Use in NYC Pilot Trial, Study Finds

In parts of New York City's Puerto Rican migrant community, people who inject drugs often do not inject themselves. They pay a ganchero — a trusted "injection doctor" who administers the shot in exchange for drugs or money. Health outreach workers have long treated that figure as part of the problem. A federally funded research team asked a different question: what if the ganchero is part of the solution?

The answer, published September 18 in the Harm Reduction Journal, is cautiously encouraging. In a pilot clinical trial supported by the National Institute on Drug Abuse, researchers built a community-driven intervention that trained gancheros to promote risk-reduction practices among their own clients — and measured what changed.

Working Through a Trusted Figure

Migrant Puerto Rican people who inject drugs face starkly disproportionate rates of HIV, hepatitis C and overdose, and earlier ethnographic work by the same team found that injection norms learned in Puerto Rico tend to persist after arrival in New York. Rather than trying to route clients around the ganchero relationship, the intervention worked through it, recruiting gancheros as conduits for sterile equipment and safer-injection norms.

The pilot ran from July 2024 to October 2025 in two New York City neighborhoods using a nonrandomized, wait-list control design: one neighborhood received the intervention first while the second served as a control, then received it in a later cycle. The baseline assessment covered 58 clients of gancheros — 28 in the first neighborhood, 30 in the second. The research office was hosted by the syringe services program BoomHealth, with implementation support from Bronx Móvil, and the protocol was pre-registered on ClinicalTrials.gov.

The two neighborhood samples were not identical at the start. Participants in the intervention neighborhood had spent less time living in Puerto Rico, re-used their own syringes more often and visited brick-and-mortar syringe programs less frequently — differences the authors flag openly in a small, nonrandomized pilot.

Promise on Infection Risk, a Puzzle on Overdose

During the first cycle, the intervention neighborhood showed a 25 percent significantly higher relative increase in past-30-day sterile syringe use compared with the control neighborhood, measured from baseline to eight months. The authors conclude that community-vetted, culturally appropriate access to sterile syringes — delivered through gancheros — holds real promise for reducing HIV and hepatitis C transmission in this population.

Naloxone told a different story. Carriage of the overdose-reversal medication rose in both neighborhoods, with no significant difference between them. The researchers describe a persistent "naloxone hesitancy" in this community as a direct challenge to overdose prevention — a reminder that getting reversal medication into the hands of people at highest risk may require its own culturally tailored approach, not just distribution.

The study's limits match its ambitions: 57 participants in the outcome analysis, two neighborhoods, no randomization. This was a pilot, funded under a NIDA developmental grant (R34DA057166), designed to show whether the model deserves a larger trial — not to settle the question. For a population that conventional outreach often fails to reach, though, the result suggests the most credible messengers may already be inside the network. When survival creates an opening, connection to opioid addiction treatment can follow — but the first bridge has to be trusted.