BACKGROUND: In January 2023, British Columbia (BC) became the first Canadian province to implement a legally sanctioned drug decriminalization policy, removing criminal penalties for adults possessing 2.5 g or less of opioids, cocaine, methamphetamine, and MDMA. Introduced as a three-year pilot, it aimed to reframe substance use as a public health issue, reduce stigma, and improve health and social service engagement. Criminal penalties were reintroduced for drug possession in most public spaces in May 2024, and the pilot ended in January 2026. Its termination has been interpreted as policy failure; this review aimed to examine how the pilot was implemented in practice and to identify factors that shaped its operationalization and early implementation-relevant outcomes.

METHODS: We conducted a systematic review with narrative synthesis of peer-reviewed literature examining implementation-relevant aspects of BC's decriminalization pilot. Six databases were searched (January-February 2026) for studies published May 31, 2022-February 1, 2026. The protocol was registered in PROSPERO (CRD420251271694).

RESULTS: Twenty-seven studies were included. Four cross-cutting implementation barriers were identified: pilot design features, public and cross-sector communication gaps, limited frontline training, and insufficient funding and infrastructure. Design features included the 2.5 g possession threshold, misalignment with real-world drug use patterns; the three-year timeframe, which constrained system-level effects; and the May 2024 amendment, which introduced additional instability. The pilot was implemented without commensurate investment in harm reduction, treatment, or housing infrastructure, within already constrained systems.

CONCLUSION: BC's decriminalization pilot suggests the effects of legal reform are shaped by implementation context. Early outcomes may reflect design features, institutional readiness, and system capacity rather than legal change alone; longer-term impacts remain uncertain. Future reforms should align legal change with coordinated implementation, operational guidance, public communication, and adequate service infrastructure.