A review finds uneven evidence on how state cannabis rules relate to use

Ongoing liberalization and legalization of cannabis policy in the United States have shifted the focus of policy discussions to how legal markets should be regulated to protect public health. We reviewed the scientific literature on cannabis legalization, mapped current state cannabis policies using the National Conference of State Legislatures cannabis policy domains, and conducted a scoping review of peer-reviewed studies from 2015 to 2026 that measured specific cannabis policies and health or use outcomes. Across the 48 included studies, evidence was concentrated in licensing and business practices, nonmedical adult use regulations, medical program regulations, and local control. Our scoping review suggests that retail availability, outlet density, proximity, and local restrictions shape cannabis exposure and use. Evidence was limited for product regulations, taxes and revenue allocation, hemp/cannabidiol policies, justice system provisions, and public health/research policies. Future research should incorporate detailed policy coding, implementation measures, market data, surveillance data, and stronger researcher-policymaker linkages.