Marijuana Users Are Being Unjustly Jailed For Allegedly Driving Under The Influence, Government-Funded Study Shows

OG article by Aaron Houston

January 1, 2026

A government-funded study published in Clinical Chemistry reveals that per se THC blood limits in nearly 20 states are leading to the unjust jailing of marijuana users who show no impairment, as THC metabolites linger in the body for days or weeks after use, unlike alcohol. The research, involving 190 heavy cannabis consumers abstaining for 48 hours before measurement and driving simulation, found that regular users often exceed zero-tolerance or per se thresholds (e.g., 2 or 5 ng/mL in 6 states, zero-tolerance in 12) long after impairment has subsided, with no strong correlation between THC levels and crash risk—effects are far weaker than alcohol's. Funded by NIH and California, the study highlights THC's lipophilic nature, detectable up to 30 days post-use, misaligning with alcohol-based laws. It echoes prior findings of inconsistent THC-crash links and calls for better methods, like field observations combined with toxicology, to identify truly impaired drivers rather than criminalizing innocent ones based on outdated science.