Updated March 22, 2024
Illicit Fentanyl and Mexico’s Role
As a primary source of, and transit country for, illicit drugs
2024. According to the U.S. Department of State’s 2024
destined for the United States, Mexico is a key factor in
International Narcotics Control Strategy Report, Mexico
U.S. drug control policy. Historically, reducing the supply
reportedly controls six fentanyl precursors: 4-
of Mexico-produced heroin and methamphetamine and the
anilinopiperidine (4-AP), 4-AP dihydrochloride, propionic
northbound flow of South American cocaine has been the
anhydride, propionyl chloride, N-phenethyl-4-piperidone
primary goal of U.S. counternarcotics policy toward
(NPP), and 4-anilino-N-phenethyl-4-piperidine (ANPP).
Mexico. Over the past five years, the focus of Mexico-
Mexico also maintains a domestic chemical control
related U.S. counternarcotics policy has shifted toward
“watchlist,” on which more than a dozen additional fentanyl
addressing synthetic opioid production and trafficking, the
precursors are listed.
diversion of precursor chemicals, and public health
considerations. U.S. counternarcotics policy also continues
Sources and Trafficking Pathways
to emphasize law enforcement cooperation to target key
At present, most U.S.-destined illicit fentanyl appears to be
organized crime figures in Mexico involved in illicit drug
produced clandestinely in Mexico, using chemical
trafficking, firearms trafficking, and money laundering.
precursors from China. Although some fentanyl precursors
are subject to international controls, as previously
Around 2019, Mexico reportedly replaced the People’s
mentioned, others may be produced and exported legally
Republic of China (PRC, or China) as the primary source of
from certain countries, including China. Mexican customs
U.S.-bound illicit fentanyl and fentanyl analogues. The
officials reportedly have struggled to detect the illicit
Biden Administration has sought to address fentanyl and
diversion of these chemicals.
fentanyl-related financial flows with unilateral actions,
through bilateral efforts under the Bicentennial Framework
Mexican transnational criminal organizations (TCOs)—
for U.S.-Mexican security cooperation, and in trilateral
particular the Sinaloa Cartel and the Jalisco New
(with Canada) and multilateral fora. Congress may continue
Generation Cartel (CJNG)—appear to be largely
to follow these efforts and contribute to their
responsible for the procurement of precursors. TCOs
implementation and oversight, including through legislative
manufacture large volumes of low-purity illicit fentanyl in
activity.
Mexico and use pill presses, often imported from China, to
lace counterfeit medication and drugs such as cocaine with
Background
fentanyl. TCOs also control the cross-border trafficking of
Fentanyl is a potent synthetic opioid that has been used
fentanyl into the United States. In the United States, local
medically as a painkiller since it was first synthesized in
affiliates of the TCOs distribute illicit fentanyl at the retail
1959. Due to fentanyl’s potential for abuse and addiction,
level.
the United Nations (U.N.) placed it under international
control in 1964. Domestically, fentanyl is regulated by the
According to the congressionally established U.S.
Drug Enforcement Administration (DEA), pursuant to the
Commission on Combating Synthetic Opioid Trafficking
Comprehensive Drug Abuse Prevention and Control Act of
(P.L. 116-92 §7221), Mexican TCO suppliers move illicit
1970, as amended (21 U.S.C. §§801 et seq.), commonly
fentanyl into the United States, primarily across the
known as the Controlled Substances Act. The U.S. Centers
southwestern border, often in passenger vehicles. The U.S.
for Disease Control and Prevention estimate that synthetic
Department of Homeland Security asserts that 90% of
opioids (primarily fentanyl-related substances) may have
fentanyl is interdicted at ports of entry, often in vehicles
resulted in more than 77,000 U.S. overdose deaths between
driven by U.S. citizens. A primary challenge for both
November 2022 and October 2023.
Mexican and U.S. officials charged with stopping the
fentanyl flow is that TCOs can meet U.S. demand with a
Traffickers appear to be marketing a growing number of
relatively small amount (measured in terms of weight).
fentanyl analogues for nonmedical, often unregulated, use.
As of May 2023, more than 30 fentanyl-related substances,
Money Laundering Trends
including precursors, were subject to international control
Opioid-related financial flows typically involve one or a
(“scheduled”) pursuant to the U.N. Single Convention on
combination of the following methods: (1) financial
Narcotic Drugs of 1961, as amended, and the U.N.
transfers involving banks, money services businesses, or
Convention Against Illicit Traffic in Narcotic Drugs and
online payment processors; (2) cryptocurrencies; and (3)
Psychotropic Substances of 1988.
other traditional drug money laundering methods, such as
bulk cash smuggling and trade-based money laundering
U.N. member states first subjected fentanyl precursors to
(TBML). The U.S. Department of the Treasury assesses
international control in 2017, agreeing to list two fentanyl
that Mexican TCOs are working with Chinese money
precursors on Table I of the 1988 Convention. U.N.
laundering organizations to repatriate drug proceeds back
member states subjected three additional fentanyl
into the Mexican banking system. There also are reported
precursors to international control in 2022 and two more in
https://crsreports.congress.gov

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Illicit Fentanyl and Mexico’s Role
connections, possibly including TBML, between Mexican
Fentanyl Committee (with Canada) and the Global
TCOs and wildlife trafficking (including to China).
Coalition to Address Synthetic Drug Threats.
Addressing Mexico’s Role
U.S. training and equipment have supported Mexico’s
The U.S. government has taken some unilateral actions to
efforts against fentanyl. In 2022, the State Department
address Mexico’s role in fentanyl production and
completed a donation of multiple, custom, high-hazard
trafficking. Since December 2021, the U.S. Department of
protective equipment kits for the safe dismantlement of
the Treasury’s Office of Foreign Assets Control has
clandestine synthetic drug labs. By 2023, more than 500
sanctioned more than 185 Mexico-based persons pursuant
U.S.-donated canines had been involved in more than 50
to E.O. 14059, some for trafficking fentanyl and other
significant fentanyl seizures. The State Department
synthetic opioids. The sanctions block assets under U.S.
reportedly has donated gas chromatography and specialized
jurisdiction, prohibit U.S. persons from engaging in
equipment to Mexico’s Prosecutor General’s Office for
financial transactions with those designated, and ban such
improved analysis of the composition of seized drugs and
persons from entry into the United States. In April 2023, the
has provided U.S. training for Mexican forensics personnel
Department of Justice indicted four of the “Chapitos,” sons
to detect fentanyl overdoses.
of Sinaloa’s jailed former leader Joaquin “El Chapo”
Guzmán, including Ovidio Guzmán, for facilitating the
Lingering barriers to cooperation reportedly include
world’s “most prolific fentanyl trafficking operation.”
corruption, a lack of resources and skilled personnel in
Mexican customs and justice institutions, and limited
In contrast to U.S.-PRC cooperation on fentanyl, which
political will in Mexico to address an issue that is seen as
yielded success in 2019 before stalling until November
primarily a U.S. problem.
2023, U.S.-Mexican cooperation on fentanyl began in 2021;
prior efforts to address synthetic drugs tended to focus on
Outlook for the 118th Congress
methamphetamine. President Andrés Manuel López
The National Defense Authorization Act for FY2024 (P.L.
Obrador (who took office in 2018) long maintained that
118-31) requires a report on cooperative efforts to target,
although fentanyl transited Mexico, fentanyl production did
disrupt, and degrade fentanyl trafficking, including limits
not occur in the country. Even as seizure data of drugs laced
on such efforts by the Mexican government (§1013). It
with fentanyl suggest fentanyl use has risen across Mexico,
requires a determination of whether the PRC government is
the government has kept naloxone—a medicine to reverse
involved in the fentanyl trade with Mexican TCOs (§1311).
opioid overdoses—tightly controlled.
The act authorizes the Secretary of Defense, in coordination
with other U.S. agencies and in collaboration with the
Bilateral counterdrug cooperation stalled from 2019 to
Mexican government as appropriate, to conduct cyber
2021. President López Obrador criticized the 2020 U.S.
operations to counter Mexican TCOs (§1505).
arrest of Mexico’s former defense minister on drug charges
and DEA activities in Mexico. He also criticized the Mérida
Congress may further shape U.S. counternarcotics policy
Initiative, a bilateral security partnership in place from
with respect to Mexico through congressional decisions
FY2008 to FY2021, and reduced security cooperation with
regarding foreign assistance funding in annual State,
the United States, except for migration enforcement.
Foreign Operations, and Related Programs (SFOPS) and
Defense appropriations acts, as well as through related
The Biden Administration has sought to reduce tensions
oversight reporting requirements. U.S. foreign assistance to
and rebuild the U.S.-Mexico security relationship. In 2021,
Mexico has declined over the past three years, with
Mexico hosted the first U.S.-Mexico High-Level Security
International Narcotics Control and Law Enforcement aid
Dialogue (HLSD) since 2016. After the dialogue, the
decreasing from $100 million in FY2021 to an estimated
governments announced a new Bicentennial Framework for
$48 million in FY2023. The reduction of such assistance
may limit Mexico’s willingness to dedicate its own
Security, Public Health, and Safe Communities focused on
protecting people, preventing transborder crime, and
resources to counterdrug efforts.
pursuing criminal networks. The Administration’s 2022
Congress also could consider unilateral policy measures
National Drug Control Strategy prioritized helping Mexico
and assess how such measures may affect bilateral
strengthen institutions with counterdrug functions and
cooperation with Mexico. A joint resolution that would
disrupting TCO illicit financial activities.
authorize U.S. military action against the TCOs in Mexico
(H.J.Res. 18) prompted harsh criticism from the Mexican
In March 2023, U.S. and Mexican officials announced
“
government. Other bills (H.Res. 216, S. 1048) seek to
phase two” of the framework, focused on combatting
designate Mexican TCOs as foreign terrorist organizations.
fentanyl production, TCOs, and arms trafficking—a key
priority for Mexico. Mexico has enacted a new law to
As Congress considers additional policy options to address
detect and punish illicit synthetic drug production,
illicit opioids sourced in Mexico, counternarcotics progress
dedicated federal prosecutors to work on fentanyl cases,
may be constrained by other policy priorities in the bilateral
extradited fentanyl trafficker Ovidio Guzmán to the United
relationship. Federal elections scheduled for 2024 in both
States, and developed a system to track diversion of dual-
countries could further reshape bilateral relations.
use chemicals. At the 2023 HLSD, U.S. and Mexican
officials highlighted increased interdictions, arrests, and
Clare Ribando Seelke, Specialist in Latin American
indictments for arms and fentanyl trafficking. The United
Affairs
States and Mexico also collaborate within the Trilateral
https://crsreports.congress.gov

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Illicit Fentanyl and Mexico’s Role

Liana W. Rosen, Specialist in International Crime and
Narcotics
IF10400


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https://crsreports.congress.gov | IF10400 · VERSION 11 · UPDATED

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