The U.S. Treasury Department announced sweeping new sanctions on Monday, October 6, 2025, targeting a sprawling network of individuals and companies in Mexico allegedly responsible for supplying the Sinaloa cartel’s notorious Los Chapitos faction with the chemicals needed to manufacture fentanyl. The move is the latest escalation in the Trump administration’s campaign against drug traffickers, as the opioid crisis continues to claim American lives at an alarming rate.
According to the Treasury’s Office of Foreign Assets Control, the sanctions impact eight Mexican nationals and a dozen Mexico-based companies. These entities, officials say, used their pharmaceutical, laboratory, chemical, cleaning, and real estate businesses to procure and distribute precursor chemicals to the Los Chapitos group, which is run by the sons of infamous former cartel leader Joaquín “El Chapo” Guzmán. The Sinaloa cartel itself has recently been designated a Foreign Terrorist Organization by the U.S. State Department, a move intended to give authorities broader powers to pursue the group’s financial networks.
“Over 500,000 Americans have died of fentanyl poisoning,” Under Secretary for Terrorism and Financial Intelligence John K. Hurley stated in the Treasury’s announcement, as reported by Border Report and the Associated Press. “President Trump has made clear that stopping the deadly flow of drugs into our country is a top national security priority. Under Secretary Bessent’s leadership, the Treasury Department is committed to dismantling the complex financial networks that support these terrorist organizations.”
At the heart of the sanctions is Sumilab S.A. de C.V., a chemical and laboratory equipment supplier based in Culiacán, Sinaloa. Sumilab was previously sanctioned in 2023 under the Biden administration, but according to the Treasury, the company’s operators—primarily members of the Favela Lopez family—simply changed the company signage, removed themselves from corporate filings, and appointed new officers while continuing to supply precursor chemicals to the cartel. International news outlets reported that Sumilab had also worked as a private contractor for both the Mexican federal government and the Sinaloa state government.
Four members of the Favela Lopez family—Jorge Luis Favela Lopez, Francisco Favela Lopez, Victor Andres Favela Lopez, and Martha Emilia—were named in the new sanctions. Two spouses associated with the family were also included. The Treasury alleges that these individuals and their companies supplied and distributed precursor chemicals and laboratory equipment to Sinaloa Cartel-affiliated chemical brokers and lab operators, enabling the production of illicit fentanyl and methamphetamine.
But Sumilab was far from the only company caught in the dragnet. Seven other businesses operated by the Favela Lopez clan—Agrolaren, Viand, Favelab, Fagalab, Qui Lab, and Storelab—were also sanctioned. Another company, Macerlab, was allegedly run by Cesar Elias Lopez Araujo, a Favela Lopez “front person,” and included in the Treasury’s list. These companies, officials say, were used as fronts to conceal the true nature of the chemical shipments and to facilitate continued operations despite previous sanctions.
The U.S. government also targeted Martha Emilia Conde Uraga, known as “Martita,” for her alleged role as a longtime Sinaloa Cartel-affiliated chemical broker. According to the Treasury, Conde Uraga utilized multiple warehouses in Culiacán and engaged in fraudulent invoicing and other concealment methods to supply precursor chemicals to drug traffickers and lab operators working for Los Chapitos. She was linked to four additional companies: Viosma, Prolimph, Proveedora de Servicios de Salud del Pacifico, and Roco—a real estate business.
The sanctions have real teeth. All property and interests in property of the designated individuals and companies that are in the United States or in the possession or control of U.S. persons are now blocked and must be reported to the Treasury Department. Any entities owned 50 percent or more by one or more blocked persons are also subject to the sanctions. In practical terms, this means that any U.S. business or individual found to be doing business with the sanctioned people or companies could face fines, criminal charges, and civil penalties.
Sumilab’s troubles began before the latest round of U.S. sanctions. In January 2024, Mexican health authorities, with the support of Mexican marines, temporarily closed the company for administrative health violations. Despite these setbacks, the company managed to maintain its operations, largely by shifting its corporate structure and using front companies, as noted by the Associated Press.
Officials say the sanctions are part of a broader strategy to choke off the financial lifelines that allow criminal organizations like the Sinaloa cartel to thrive. The Trump administration’s decision to designate the cartel as a Foreign Terrorist Organization marks a significant shift, reflecting a more aggressive approach to targeting drug-trafficking groups that are, as Under Secretary Hurley put it, “largely non-political and more focused on raking in profit.”
President Trump himself underscored the seriousness of the administration’s stance last week, declaring that the U.S. is in an “armed conflict” with drug cartels. This came on the heels of U.S. military strikes on boats allegedly carrying drugs in the Caribbean—a move that has rattled much of Latin America, according to AP reporting.
The investigation that led to Monday’s sanctions was a collaborative effort involving several U.S. agencies. Customs and Border Protection’s National Targeting Center, the FBI’s Phoenix Field Office, the Drug Enforcement Administration’s Tampa and Rocky Mountain field offices, and Homeland Security Investigation’s Newark office all participated, according to Border Report.
For families affected by fentanyl poisoning, the announcement brings a measure of hope that the U.S. government is taking meaningful action. Still, the scale of the crisis is daunting: more than half a million Americans have died from fentanyl poisoning, a staggering figure that underscores the urgency of the fight.
While the sanctions represent a significant step, officials acknowledge that the battle is far from over. The adaptability of the sanctioned companies—especially Sumilab, which managed to continue operations despite previous penalties—highlights the challenges authorities face in dismantling such sophisticated networks. The Sinaloa cartel and its affiliates have shown a remarkable ability to shift tactics and exploit legal and regulatory loopholes, keeping law enforcement perpetually on their toes.
The Trump administration’s aggressive approach has sparked debate both in Washington and abroad. Some praise the move as a necessary escalation in the fight against deadly drugs, while others worry about the broader implications of labeling criminal organizations as terrorist groups, especially given their profit-driven, non-political nature. Meanwhile, Mexican authorities continue to grapple with their own enforcement challenges, often caught between international pressure and local realities.
As the U.S. government tightens the noose on cartel-linked chemical suppliers, the world will be watching closely to see whether these measures can finally disrupt the deadly flow of fentanyl—and whether the cartels themselves can be brought to heel.
