How have fentanyl synthesis methods and precursor supplies evolved since 2020?
This fact-check may be outdated. Consider refreshing it to get the most current information.
Executive summary
Since 2020, illicit fentanyl production has shifted through three measurable trends: clandestine chemistry diversified from older Janssen/Siegfried routes toward “one‑pot” and Gupta‑style methods that simplify precursors and production (e.g., Gupta/one‑pot dominance in 2021 seizures) [1]; governments and the UN have moved to schedule additional precursors (three added to international control in 2022) while states like the U.S. have listed key chemicals domestically [2] [3]; and enforcement and investigative reporting show China remained the principal source of precursor chemicals even as India emerged as an increasingly notable supplier by 2024–25 [4] [5] [6]. Available sources do not mention detailed laboratory protocols beyond those summarized in public reports.
1. Methods simplified: from multi‑step to one‑pot and back again
Academic and forensic literature and seized‑sample testing document a shift away from only the classic Janssen and Siegfried multistep syntheses toward simpler procedures used by clandestine manufacturers. Scientific reviews list the Janssen, Siegfried, Gupta (one‑pot) and Suh methods as the main published options, and U.S. testing found Gupta‑style routes predominant in early 2021 seizures, reflecting a move to fewer steps and easier skill requirements [1] [7]. Forensic chemical‑attribution work shows distinct chemical signatures associated with different methods and confirms multiple routes remain in use [8].
2. Precursors moved onto control lists — but many remain available
International and domestic controls expanded after 2017: UN member states added three more fentanyl precursors to Table I of the 1988 Convention in March 2022, and the U.S. has designated benzylfentanyl and 4‑anilinopiperidine as List I chemicals and later pursued controls on reagents like propionyl chloride [2] [3] [9]. Policymakers emphasize scheduling to choke supply, but analysts warn there are thousands of potential alternative chemicals that can serve as precursors, complicating full containment [10].
3. Supply chains: China stays central; India rises as a focal point
Investigations and government reporting repeatedly identify companies in the People’s Republic of China as the largest source of fentanyl precursors and related equipment into global supply chains through the mid‑2020s [11] [12]. Major investigative series and enforcement reporting documented how easily many precursor chemicals were bought from Chinese suppliers online [13]. By 2024–25, U.S. and financial authorities increasingly flagged Indian firms and nationals in precursor procurement cases, indicating diversification of upstream suppliers [5] [6].
4. Enforcement response altered industry behavior but did not eliminate precursors
Heightened seizures, trafficking indictments, and controls have pressured illicit networks and produced observable shifts in supply chains — for example, U.S. enforcement actions and international scheduling coincided with seizures of new classes of precursors and changes in synthesis impurities detected in forensic labs [14] [2]. At the same time, public reporting and financial‑crime analyses show cartels and brokers use front companies, intermediaries and global logistics to continue procuring chemicals, limiting the impact of controls alone [15] [13].
5. Forensics and chemical signatures reveal route switching
Laboratory attribution studies and analyses of seized samples from 2020–2023 identified route‑specific impurities and intermediates (e.g., N‑BOC norfentanyl and other unique by‑products) that indicate ongoing use of multiple synthetic routes and occasional switches between them — a sign traffickers adapt to precursor availability or enforcement pressure [14] [8].
6. Competing narratives: regulation versus industry limits
Governments and enforcement agencies emphasize scheduling and interdiction to reduce supply; China’s official statements describe strict domestic controls and export approvals for listed precursors [16] [11]. Independent reporting and academic analyses counter that many precursors remain legally used in industry and academia, are easily purchased online, and that thousands of chemicals could be repurposed for fentanyl manufacture — meaning scheduling is necessary but not sufficient [13] [10].
7. What reporting does not (yet) say
Available sources do not publish step‑by‑step clandestine lab protocols beyond high‑level mentions of the Janssen/Siegfried/Gupta/Suh methods or forensic impurity patterns; they do not provide comprehensive counts of all alternate precursor chemicals actually diverted in every market [7] [1] [10]. For policymakers and journalists, that lack of granular lab‑level public data is a practical limitation for assessing how quickly illicit chemists can substitute reagents.
Bottom line: since 2020 the illicit fentanyl industry has become more adaptable — moving toward simpler synthesis routes where feasible, relying on a global market for precursors (historically centered in China with growing Indian links), and responding to scheduling and enforcement by changing suppliers and methods. Official controls have narrowed some pathways [2] [3], but public reporting and forensic evidence show persistent diversification of precursors and methods keeps the overall problem resistant to supply‑side fixes alone [13] [10].