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"It Just Puts You Out!" 'Tranq Sleep,' Sensory Discernment, and the Experience of Consuming Xylazine-Adulterated Fentanyl in Rural North Carolina.

Claudia Squire, Aminah Isiaq, Nicholas Peiper, Michelle Mathis, Jon E Zibbell

medRxiv October 30, 2026 preprint DOI: 10.64898/2026.10.30.26366218 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Qualitative study
Sample size 25
Population Fentanyl consumers recruited from fixed and mobile syringe service programs in west-central North Carolina
Key findings Participants described sensory strategies for detecting xylazine in fentanyl (residue appearance on foil, bitterness and chemical odor when smoked, altered viscosity when injected), though a minority could not detect it by sensory cues. Participants distinguished a profound involuntary sedation they called "tranq sleep" from the opioid nod, characterized by near-instantaneous loss of consciousness and severe withdrawal upon awakening. Nearly all expressed strong aversion to xylazine, while a meaningful minority valued its amplifying effects on a diminishing fentanyl high.

Abstract

Xylazine, a veterinary sedative not approved for human use, has emerged as a consequential adulterant in the U.S. illicit fentanyl supply. Although a growing body of qualitative research has documented the experiences of fentanyl consumers exposed to 'tranq' in large Northeastern cities, little is known about how xylazine is experienced in rural or Southern regions where the evolution of the illicit drug supply often lags behind its urban equivalents. This study examines how fentanyl consumers in west-central North Carolina detect, comprehend and respond to the widespread adulteration of fentanyl markets with xylazine. Between September and December of 2025, a seasoned interviewer conducted 25 in-depth, semi-structured qualitative interviews with fentanyl consumers recruited from both fixed and mobile syringe service programs in west-central North Carolina. Interviews explored sensory discernment strategies, pharmacologic effects, and behavioral responses to the presence of xylazine. Data were analyzed using a combined deductive-inductive thematic approach in QSR NVivo 14.0. Participants described a distinctive repertoire of sensory strategies for identifying xylazine in their fentanyl supply, including the appearance of drug residue on foil, bitterness and chemical odor when smoked, and altered viscosity when injected. A minority described an inability to detect xylazine through sensory cues. Participants consistently distinguished a profound involuntary sedation they called "tranq sleep" from the familiar opioid nod, characterizing it by nearly instantaneous loss of consciousness with severe withdrawal upon awakening. While nearly all participants expressed strong aversion to xylazine, a meaningful minority valued its amplifying effects to 'improve' a diminishing fentanyl high. This study offers among the first qualitative description of xylazine exposure in a rural fentanyl market. Findings extend the xylazine literature geographically and pharmacologically and underscore the urgency of harm reduction responses tailored to the distinctive harms of xylazine. In particular, adverse health outcomes that accumulate during episodes of protracted and unarousable sedation, including physical injury, victimization, and the severe withdrawal syndrome that follows upon awakening. xylazine; tranq sleep, fentanyl; qualitative methods; harm reduction; rural drug markets; drug discernment.

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