INSIGHTi

Xylazine: Considerations for Federal Control
February 2, 2023
Xylazine is a sedative drug used in veterinary medicine. It is not approved or intended for human
consumption. Some drug users intentionally consume xylazine in combination with drugs of abuse, such
as illicit fentanyl, to strengthen its effects, while other users are unaware that xylazine is sometimes added
to illicit opioids as an adulterant. Xylazine is also used in drug-facilitated crimes to induce a state of
unconsciousness. The Food and Drug Administration (FDA) and Drug Enforcement Administration
(DEA) have issued warnings regarding the risks of humans consuming xylazine, and media reports
indicate the substance is worsening addiction and causing physical wounds among those who use illicit
opioids.
Xylazine is not currently controlled under the Controlled Substances Act (CSA). As Congress weighs the
legitimate use of xylazine and the risk it poses to public safety and health, it might consider making it a
controlled substance under the CSA, thereby allowing DEA to regulate the substance.
The Legitimate Use and Adverse Effects of Xylazine
Veterinarians use xylazine on horses and cervidae (e.g., deer, elk) animals as a sedative and pain reliever.
According to FDA, “it is not safe for use in humans and may result in serious and life-threatening side
effects that appear to be similar to those commonly associated with opioid use, making it difficult to
distinguish opioid overdoses from xylazine exposure.” Xylazine can increase the risk of fatal overdose
because it can cause respiratory depression, low blood pressure, and slowed heart rate.
Xylazine is not an opioid, and therefore overdose reversal drugs, such as naloxone, do not counteract its
effects. According to the Centers for Disease Control and Prevention (CDC) naloxone may be less
effective in reversing an opioid-related overdose if illicit opioid substances contain xylazine because
xylazine can heighten the sedation and respiratory effects of opioids. Several states have reported
increases in xylazine-involved overdose deaths, although the prevalence of xylazine in drug overdose
deaths has not been extensively studied. Media reports indicate that xylazine consumption in humans can
cause “wounds that erupt with a scaly dead tissue” that left untreated can lead to the need for amputation.
FDA further reports that it is unclear if the xylazine being misused by humans is illicitly manufactured
(and therefore unapproved by FDA) or diverted from legitimate medical use. DEA reports increasing
xylazine encounters across the United States, most commonly in the Northeast. The substance is
frequently found in polydrug mixtures, often in mixtures containing illicit fentanyl.
Congressional Research Service
https://crsreports.congress.gov
IN12086
CRS INSIGHT
Prepared for Members and
Committees of Congress

---

Congressional Research Service
2
Current Status of Xylazine and Considerations in Scheduling
As of the date of this Insight, xylazine is not a controlled substance under the CSA. Xylazine is subject to
regulation under the Federal Food, Drug, and Cosmetic Act and some state laws.
Because xylazine is not scheduled under the CSA, DEA currently does not have the authority to control it.
Either Congress or DEA (in conjunction with FDA) could decide to schedule xylazine. The CSA-required
process for DEA and FDA to schedule a substance can be time consuming, whereas Congress may pass
(and the President may sign) a bill scheduling a substance and is not bound by the CSA’s procedural
requirements.
Scheduling under the CSA
The CSA established five schedules in which substances may be classified. Schedule I is the most restrictive, containing
substances with no accepted medical use and a high potential for abuse. Scheduling control ed substances normally occurs
through designated procedures.
Permanent Scheduling Procedures
The Attorney General (AG), through DEA, and in consultation with the Department of Health and Human Services/FDA,
may place substances into schedules under the CSA based upon eight factors: (1) actual or relative potential for abuse; (2)
known scientific evidence of pharmacological effects; (3) current scientific knowledge of the substance; (4) history and
current pattern of abuse; (5) scope, duration, and significance of abuse; (6) risk to public health; (7) psychic or physiological
dependence liability; and (8) whether the substance is an immediate precursor of an already-scheduled substance. Congress
may also add a substance to a schedule through legislation.
Temporary/Emergency Scheduling Procedures
In 1984, Congress gave the AG the authority to temporarily place a substance into Schedule I of the CSA to “avoid
imminent hazards to public safety.” To do so, the AG (through DEA) must consider the drug’s history and current pattern
of abuse; scope, duration, and significance of abuse; and risk to public health. Emergency scheduling may be used to place
substances into Schedule I only. It may last for up to two years, with a one-year extension available in some circumstances.
The regulatory controls that apply to a substance depend on the schedule in which it is classified.
Congress or DEA could schedule xylazine in Schedules I-V or decide not to schedule xylazine at all.
Given that xylazine has accepted use in veterinary medicine, it is unlikely DEA would take steps to
emergency schedule it and place it in Schedule I. Placement in Schedule II would affect the availability
and handling of xylazine, but, unlike a Schedule I placement, it would still be available for accepted
medical use. As a Schedule II controlled substance, it would be subject to annual quota limitations,
stricter storage requirements than uncontrolled substances or those on Schedules III-V, and other more
stringent DEA regulations.
Scheduling a substance has implications for those who violate the CSA, as well as for the federal criminal
justice system as a whole. Penalties for illicit manufacturing, possession, and trafficking of controlled
substances range from fines to life in prison and some CSA crimes are punishable by death, depending on
a number of factors pursuant to the crime. Factors considered in federal sentencing include, but are not
limited to, the number of offenders, the schedule and quantity of the drug, the number of prior offenses,
and aggravating factors (e.g., causing death, weapons involved). As of the date of this Insight, of the
147,921 federal inmates for whom offense data are known, 66,569 (45%) are serving sentences for federal
drug offenses. It is unknown whether or how the relative number of drug offenders might change if
xylazine were to be scheduled.

---

Congressional Research Service
3
Author Information

Lisa N. Sacco
Hassan Z. Sheikh
Analyst in Illicit Drugs and Crime Policy
Analyst in Health Policy





Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff
to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of
Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of
information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role.
CRS Reports, as a work of the United States Government, are not subject to copyright protection in the United
States. Any CRS Report may be reproduced and distributed in its entirety without permission from CRS. However,
as a CRS Report may include copyrighted images or material from a third party, you may need to obtain the
permission of the copyright holder if you wish to copy or otherwise use copyrighted material.

IN12086 · VERSION 1 · NEW

---