Utah's Metabolite DUI Law
Utah Code § 41-6a-517 prohibits driving with any measurable controlled substance metabolite in the body. This means THC metabolites from marijuana use days or weeks earlier can result in a DUI charge. You do not need to be impaired at the time of driving — just having the metabolite is enough.
The Marijuana Problem
THC metabolizes into THC-COOH, which stores in fat cells and is detectable for days to weeks after use — long after any impairment has passed. A driver who used marijuana legally in Nevada and drove in Utah days later could theoretically be charged under § 41-6a-517 with zero actual impairment. Utah's medical cannabis program does not provide a defense to metabolite DUI.
Prescription Drug DUI
Legitimately prescribed medications — opioids, benzodiazepines, sleep aids, muscle relaxants — can support both a metabolite DUI and an impairment-based DUI if an officer believes the medication affected driving. The fact that it was lawfully prescribed is a mitigating factor but not a complete defense.
Drug Recognition Experts (DRE)
When drug impairment is suspected, officers may call a Drug Recognition Expert — an officer trained in a 12-step evaluation protocol. DRE testimony is admissible in Utah courts, but the protocol and conclusions can be challenged point by point.
Call (801) 627-1110 for a free case assessment on your drug DUI case. Available 24/7.