HOW LONG DOES MARIJUANA STAY IN YOUR SYSTEM FOR MISSOURI DUI CASES?

With recreational marijuana now legal in Missouri, more people are wondering how cannabis use affects DUI charges.

One of the biggest questions we hear is: “How long does marijuana stay in your system?”

This matters because Missouri law allows police and prosecutors to use blood or urine tests in DUI/DWI cases involving marijuana. The problem? THC (the active ingredient in marijuana) can stay in your body long after you’re no longer impaired — meaning you could test positive even when you’re perfectly sober.

If you have been charged with a DWI or DUI in Missouri while under the influence of marijuana, call KC Defense Counsel today. Our experienced Kansas City DWI lawyers can help you sort through the often confusing Missouri legal system.

THC VS. IMPAIRMENT

Unlike alcohol, which has a clear legal limit of 0.08% BAC, Missouri has no legal THC limit for drivers. Instead, prosecutors rely on drug tests and officer observations to argue that you were impaired.

The issue is that:

• THC can linger in your system for days or even weeks.
• Impairment only lasts a few hours after use.

This disconnect means you could face DUI charges based on THC levels that don’t reflect your actual ability to drive safely.

HOW LONG DOES MARIJUANA STAY IN YOUR BODY

Detection depends on how often you use cannabis, the amount consumed, and the type of test used.

Blood Tests: Detect THC for up to 12–24 hours in occasional users, and up to a week in frequent users.

Urine Tests: Can detect THC metabolites for several days in occasional users, and up to 30+ days in heavy, daily users.

Saliva Tests: Usually detect THC for up to 24–48 hours.

Hair Tests: Rarely used in DUI cases, but can show marijuana use for up to 90 days.

This means that even if you haven’t smoked in days, you could still test positive in a Missouri DUI investigation.

WHY THIS CREATES PROBLEMS IN MISSOURI DWI CASES

Because THC lingers so long, drug test results don’t necessarily prove you were impaired at the time you were driving. For example:

• A regular cannabis user may test positive even if they haven’t used in a week.
• An occasional user may test positive the next day, even though the high wore off hours earlier.

That’s why DUI cases involving marijuana in Missouri are often more complex than alcohol DUIs. Prosecutors must rely on a mix of officer testimony, field sobriety tests, and drug tests to build their case and that gives your defense lawyer room to fight back.

DEFENDING AGAINST MARIJUANA DWI/DUI CHARGES IN MISSOURI

Our affordable Missouri DUI defense lawyer in Kansas City can challenge marijuana DUI cases by:

• Questioning whether the traffic stop was legal.
• Attacking the reliability of field sobriety tests.
• Challenging the accuracy of THC testing.
• Presenting evidence that THC in your system did not equal impairment.

In many cases, the prosecution’s evidence isn’t as strong as it seems, and skilled defense can mean the difference between a conviction and a dismissal.

HIRE AN EXPERIENCED KANSAS CITY DUI LAWYER IMMEDIATELY

At KC Defense Counsel, we’ve defended countless clients in Missouri DUI cases, including those involving marijuana. We understand how prosecutors use drug tests and we know how to challenge them in court.

• Marijuana is legal in Missouri, but driving under the influence is still illegal.
• THC can stay in your system for days or weeks, depending on usage.
• Testing positive doesn’t always mean you were impaired at the time of driving.
• Marijuana DUI cases are highly defendable with the right attorney.

Criminal charges in Missouri can have lifelong consequences, from fines and jail time to lost career opportunities. The team at KC Defense Counsel understands the stakes, and we’re ready to challenge the evidence, protect your rights, and fight for the best possible outcome. Whether you’ve been arrested for DUI, assault, drug possession, or any other offense, our Kansas City criminal defense lawyers are here for you 24/7.

If you’ve been charged with a marijuana DUI in Kansas City, don’t wait. Call KC Defense Counsel today for a free case evaluation with an experienced Missouri DUI defense attorney.

We’ll fight to protect your record, your license, and your freedom.

Cities we serve: Adrian, Archie, Bates City, Belton, Blue Springs, Buckner, Butler, Cameron, Claycomo, Cleveland,  Drexel, Fairview,  Ferrelview,  Gladstone, Grain Valley, Grandview, Greenwood, Houston Lake, Independence, Kansas City Missouri, Kearney, , Knob Noster, Lake Lotawana, Lake Tapawingo, Lake Waukomis, Lake Winnebago, Lawson, Lee’s Summit, Liberty, North Kansas City, Oak Grove, Oakview,  Parkville, Peculiar,, Platte City, Platte Woods, Plattsburg, Pleasant Hill,  Raymore, Raytown, Riverside, Smithville, Sugar Creek, Tracy,  Warrensberg, Weatherby Lake, and Weston.

Statewide: Missouri State Highway Patrol and Sheriff Counties we serve: Bates County, Cass County, Clay County, Jackson County, Platte County, Ray County.

Contact our experienced Kansas City traffic defense lawyers near me in Missouri and let us help begin building your defense. Let us help.

Disclaimer: This page is for informational purposes only and does not create an attorney-client relationship. Always consult qualified counsel regarding your unique situation.