A Chainalysis report reveals that cryptocurrency payments to suppliers of fentanyl precursor chemicals began declining in mid-2023, months before a decrease in overdose deaths was recorded. This suggests that blockchain data could serve as an early indicator of disruptions in the illicit drug supply chain, potentially offering a three-to-six-month lead time over traditional public health data. The report also highlights a significant increase in cryptocurrency activity linked to human trafficking networks, particularly in Southeast Asia. In 2025, crypto flows to these networks surged by 85% year-over-year, reaching hundreds of millions of dollars. Chainalysis identified four main categories of crypto-facilitated trafficking, including "international escort" services and child sexual abuse material vendors, with varying payment patterns and operational structures.