This Week’s Focus: Heroin

NDEWS has been monitoring and contributing data that show a reduction in drug overdoses. However, from discussions with our scientific advisory group (SAG) members and other NDEWS affiliates, this week we decided to explore the possibility of a new signal related to an increase in heroin use. While overall encounters declined nationally, Western states reported a slight increase in heroin use, which contrasts with steady declines in Central and Eastern states.

This emerging data is also supported by the Millennium Health Signals Report Vol. 7, published in February 2025, which found heroin detection among fentanyl-positive samples rose 28% in Western states (18% nationally) from 2023 to 2024.

New studies featured in this week’s Briefing reinforce heroin’s persistence in certain target areas, which highlights the immediate need for continuing naloxone distribution and treatment.

Out of 301,321 total EMS encounters for nonfatal overdoses from July 2024 to April 2025, 23,196 (7.7%) involved heroin. Of those heroin-related encounters, 1,586 (6.8%) occurred in western states, 8,878 (38.3%) in Central states and 12,732 (54.9%) in Eastern states. However, the data shows a statistically significant increase in nonfatal heroin-related EMS encounters in the western states, in contrast to the declining trends observed in Central and Eastern states and nationally overall.

To view the entire Special Report from our Weekly Briefing, click here.
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Why are we focusing on heroin this week? As noted above, while heroin overdoses have decreased across the US, we have heard from our NDEWS network that there are hotspots where heroin overdose has increased.

What is heroin? Heroin (diacetylmorphine) is a semi-synthetic opioid derived from morphine. It produces intense euphoria, pain relief, and sedation. Heroin has different onset times and intensities of effects depending on the route of administration.

Public health impact: Many Reddit commenters reported negative physical side effects associated with heroin injection including endocrine disruptions and infections. Many commenters who wished to quit heroin had trouble finding information on how to transition to medication-assisted treatment, and avoiding precipitated withdrawal.

How is it being discussed? Many Reddit commenters report difficulty finding authentic heroin, which has been increasingly replaced by fentanyl and "tranq dope" (xylazine-cut opioids). Commenters frequently express nostalgia for "real" heroin, noting a preference for its more gradual onset and sustained effects compared to fentanyl. Commenters report that testing results reveal that products advertised as primarily heroin contain very little heroin content, instead consisting mostly of fentanyl and various adulterants.

Regional variations in availability are commonly discussed, with European users reporting more consistent access to unadulterated heroin compared to their US counterparts. Some users note that "tan dope," primarily available in the southeast US, exhibits characteristics similar to genuine heroin. Discussions about "tranq dope" (heroin/fentanyl cut with xylazine or other sedatives like medetomidine) are widespread across these forums.

Many posts focus on transitioning from heroin to medication-assisted treatment, particularly buprenorphine (Suboxone) and methadone, with users frequently seeking advice about avoiding precipitated withdrawal when initiating these medications. These discussions often compare withdrawal experiences, with consistent reports that fentanyl withdrawal is more severe but shorter in duration than heroin withdrawal. Some users also discuss long-term consequences of heroin use, including endocrine disruption and infections from injection requiring hospitalization.

Drug terms: Heroin, Chivas

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A recently published analysis in the Millennium Health Signals Report Vol. 7 found that heroin co-detection in fentanyl-positive urine samples increased from 23.2% in Q1 2024 to 31.5% in Q4 2024—a relative increase of 18%. Regionally, the largest spikes occurred in the West (25.2% to 32.2%; +28%), Midwest (25.4% to 31.8%; +25%), and South (23.8% to 28.1%; +18%). This signal reverses a multi-year decline in heroin detection and may reflect rising availability, changing preferences, or shifts in the composition of fentanyl-adulterated supplies.
Read the report here.

A recently published study in Addiction Science & Clinical Practice by Pytell et al. compared past-year heroin and illicitly manufactured fentanyl (IMF) use estimates using two nationally representative surveys: the National Survey on Drug Use and Health (NSDUH) and the Survey of Non-Medical Use of Prescription Drugs (NMURx). Findings from 2022 data showed that heroin or IMF use was twice as prevalent in NMURx (1.05%) compared to NSDUH (0.52%), highlighting possible underestimation in household-based surveys like NSDUH. Despite methodological differences, both surveys showed similar correlates of heroin or IMF use, including comorbid stimulant and benzodiazepine use, and lower income.
Read the study here.

A study published in the International Journal of Drug Policy by Gonzalez-Nieto, et al., analyzed 8122 opioid samples from British Columbia, Canada, collected between January 2021 and December 2023. Fentanyl and its analogues were found in 88% of samples, with fluorofentanyl rising to 70% by 2023. Heroin was detected in only 4% of samples. Benzodiazepines were present in 49% of samples, with a shift from etizolam to bromazolam. The median concentrations were 10.6% for fentanyl and 3.2% for bromazolam. Read the study here.

A study published in American Journal of Preventive Medicine by Sauda et al., examined sex-specific trends in methamphetamine-related mortality in the US from 1999 to 2021. Data used from the CDC WONDER database, found that methamphetamine-related mortality rates increased 58.8-fold among males and 65.3-fold among females during this period. The proportion of deaths involving heroin and/or synthetic opioids also rose significantly for both sexes. The study highlights the need for robust harm reduction efforts, particularly for individuals who co-use stimulants and opioids.
Read the report here.

The study published in JAMA Network Open by Vickers-Smith, et al., investigated the use of fentanyl test strips (FTS) among people who use drugs (PWUD) and their association with overdose risk reduction behaviors. Conducted from May to December 2023, as part of the HEALing Communities Study, this multisite, observational cohort study involved 732 participants from Kentucky, New York, and Ohio. The findings suggest that FTS use is linked to greater engagement in behaviors that reduce overdose risk, such as having naloxone nearby, testing drug strength, and asking someone to check on them while using drugs. However, there was no significant difference in self-reported nonfatal overdoses between FTS users and nonusers.
Read the report here.

The study published in the International Journal of Drug Policy by Le et al., surveyed 381 people who use drugs (PWUD) across eight Southeastern US cities. It found that while 82% of PWUD had heard of naloxone, only 43% had received training to use it. Despite this, there was a strong willingness among PWUD to be trained, carry, and use naloxone, with a median willingness score of 5.00 on a 5-point scale. The main barrier to naloxone use was not knowing where to go for training. PWUD suggested strategies to improve naloxone distribution, including offering training at their sites, increasing access to naloxone education, and connecting people to training programs. 
Read the report here.

A study published in International Journal of Drug Policy by Daniulaityte et al., explored the perceptions of overdose risks among users of fentanyl-laced counterfeit pills, known as "blues," in Phoenix, Arizona. Conducted between November 2022 and December 2023, the study involved qualitative interviews with 60 participants. Despite 55.3% having prior overdose experiences, 62.2% rated their current risk as none or low, viewing smoking as safer than injection. Participants highlighted the unpredictability of "blues" and the importance of trusted sources. 
Read the report here.

A press release by the DEA reports that over 620,000 pounds of expired and unused medications were collected nationwide during the 28th National Prescription Drug Take Back Day in April 2025. The DEA New Orleans Division alone removed 41,348 pounds across Alabama, Arkansas, Louisiana, and Mississippi. Since 2009, the initiative has cleared nearly 19.8 million pounds from homes, helping prevent misuse. Nearly 17,000 authorized collectors nationwide offer year-round drop-off options. Visit [Every Day is Take Back Day] to find a site.
Read the report here.

You are invited to attend the NDEWS Summit at the College on Problems of Drug Dependence (CPDD) 87th Annual Scientific Meeting on Saturday, June 14th (06/14/2025) from 4:00 pm - 6:00 pm CT in Bayside Ballroom AB, 4th floor. The Summit will be open to all CPDD meeting attendees. 

We hope to see you there!

NDEWS Posters and Presentations at CPDD

In June, the NDEWS team will be traveling to attend the 87th College on Problems of Drug Dependence (CPDD) Annual Meeting in New Orleans, Louisiana. Along with posters, the NDEWS team will be presenting a late-breaking abstract, an oral presentation and two invited symposia. We invite you to join us for these presentations. Please find the presentation information below:

Sunday, June 15
3:30 pm - 4:45 pm CT Late-Breaking Abstract
Anesthetics (“-Caines”) Adulterate the Illicit Fentanyl Supply: A National Drug Early Warning System (NDEWS) Alert
Joseph Palamar, Joshua DeBord, Alex Krotulski, Bruce Goldberger

5:00 pm - 6:30 pm CT Poster Session 1 (Napoleon Ballroom CD, 3rd Floor)
Trends in Nonfatal Fentanyl Poisonings Involving Stimulants in the United States, 2015–2023
Nicole Fitzgerald, Joshua Black, Linda Cottler, Silvia Martins, Joseph Palamar

Monday, June 16
10:45 am - 12:15 pm CT Invited Symposium
Found in Translation: Coordinated Preclinical, Human Laboratory and Epidemiological Approaches to Understanding Polydrug Use
William Stoops, Lori Knackstedt, Linda Cottler, Christa Corley

3:30 pm - 4:30 pm CT Oral Session: Sex Matters: Translational Evaluations of Sex-Specific Factors in Substance Use
Sex Differences in Problematic Substance Use, Mental Health, and Social Determinants of Health among Middle-Aged and Older Adults in the All of Us Research Program
Vijaya Seegulam, Bia Whipp, Liva LaMontagne, Linda Cottler

5:45 pm - 7:15 pm Poster Session 2 (Napoleon Ballroom CD, 3rd Floor)
Natural Language Processing Analysis of 7-Hydroxymitragynine Reddit Discussion
Daniel Van Zant, Kirsten Smith, Oliver Grundmann, Catherine Striley, Elan Barenholtz, Christopher McCurdy, Linda Cottler

Tuesday, June 17
3:45 pm- 4:45 pm CT Oral Presentation at Mini Symposium: Prevalence and Characteristics of Recreational Ketamine Use among Nightclub Attendees and College Students in the New York Tristate Area.
The Current Landscape of Medical and Recreational Ketamine Use
Shahar Almog, Meredith Berry, Joseph Palamar 

5:30 pm - 7:00 pm CT Poster Session 3 (Napoleon Ballroom CD, 3rd Floor)
Reported Use of Recreational and Medical Cannabis, Delta-8, and Delta-10: Findings from NDEWS Sentinel Sites and Hotspots (2022–2023)
Tamara Millay, Vijaya Seegulam, Monica Bhargavi Kodali, Linda Cottler

Wednesday, June 18
2:00 pm - 3:30 pm CT Poster Session 4 (Napoleon Ballroom CD, 3rd Floor)
Alcohol Polysubstance Use among past 30-Day Opioid Users in Northern Florida: A Model for Back Translational Research
Christian Conger, Linda Cottler

Friday, June 20
3:00 pm - 5:00 pm CT Polysubstance Use: From Bench to Communities Session 2 Keynote (LSU Health Sciences Center, 411 S Prieur Street, New Orleans, LA 70112)
The National Drug Early Warning System Networks, Initiatives and Data: How can we help?
Linda Cottler

📅 Dates: May 21, 2025

🕑 Time: 3:00 pm ET

📍 Location: Online

Learn more here.

📅 Dates: May 29 - May 30, 2025

📍Location: UF Academic and Research Center at Lake Nona, Orlando, FL

Learn more here.

📅 Dates: June 2 - 4, 2025

📍 Location: University of Puget Sound, Tacoma, WA

Learn more here.

📅 Date: Thursday, June 12, 2025

🕑 Time: 12:00 pm ET

📍 Location: Online

Learn more here.

📅 Date: Friday, June 20, 2025

📍 Location: New Orleans

Learn more here.

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If you miss or want to learn more about NDEWS Original Content, you can find our archived content on the NDEWS website:

     • NDEWS Hotspot Alerts using substance-related EMS data
     • NDEWS Rapid Street Reporting (RSR) survey data reports
     • NDEWS Web Monitoring Team Reddit Alerts
     • NDEWS Sentinel Site Reports
     • Previous issues of the NDEWS Weekly Briefings

The Weekly Briefing is a newsletter published each week by the National Drug Early Warning System (NDEWS) Coordinating Center, which is funded by the National Institute on Drug Abuse (U01DA051126) to the University of Florida (MPI: Cottler (contact), Co-Is: Goldberger, Nixon, Striley), New York University (MPI: Palamar), and Florida Atlantic University (Co-I: Barenholtz). Any item may be reproduced provided the source is acknowledged.