U.S. State Marijuana and Delta-8-Tetrahydrocannabinol Laws and Delta-8-Tetrahydrocannabinol Use

Delta-8-tetrahydrocannabinol has gained popularity since the passage of the 2018 U.S. Farm Bill. The absence of federal laws and varying state regulations governing delta-8-tetrahydrocannabinol have allowed manufacturers to evade restrictions placed on marijuana products. This study examined delta-8-tetrahydrocannabinol use across different state marijuana and delta-8-tetrahydrocannabinol policies. A cross-sectional, web-based survey of 1,523 U.S. adults was conducted in October-November 2023. Responses were weighted to represent the national adult population. Inverse-probability-of-treatment weights balanced covariates across policy groups; adjusted risk ratios and 95% CIs were estimated in 2025 for state (1) marijuana policy (prohibited, medical only, recreational) and (2) delta-8-tetrahydrocannabinol policy (prohibited, regulated, unregulated). Approximately 7.7% (95% CI=6.5, 9.1) of U.S. adults reported using delta-8-tetrahydrocannabinol in their lifetime. The prevalence of delta-8-tetrahydrocannabinol use was lower among adults in states permitting recreational marijuana use (5.5%; adjusted risk ratio=0.48, 95% CI=0.33, 0.70) and lower in states permitting medical use only (8.5%; adjusted risk ratio=0.73, 95% CI=0.46, 1.14) than in states prohibiting all marijuana use (10.9%). Adults in states that regulated (3.9%; adjusted risk ratio=0.33, 95% CI=0.20, 0.55) or prohibited (4.5%; adjusted risk ratio=0.47, 95% CI=0.28, 0.78) delta-8-tetrahydrocannabinol sales reported lower rates of delta-8-tetrahydrocannabinol use than adults in states with unregulated markets for delta-8-tetrahydrocannabinol (10.5%). Delta-8-tetrahydrocannabinol use is more common where marijuana remains prohibited and less common where delta-8-tetrahydrocannabinol sales are regulated or prohibited. State-level restrictions targeting delta-8-tetrahydrocannabinol appear to reduce use, suggesting that closing regulatory gaps could limit consumption of these products.