Facing a marijuana-related DUI charge in South Carolina? Here's what the law actually says — and how a DUI lawyer in Greenville, SC can fight for your rights.
Many South Carolinians assume that marijuana-related driving charges are handled differently than alcohol-based DUIs. They aren't. Under South Carolina law, getting behind the wheel after using marijuana can lead to the exact same DUI penalties as an alcohol-based DUI, including jail time, license suspension, Ignition Interlock Device, heavy fines, and a permanent mark on your criminal record.
If you've been pulled over and charged with DUI involving marijuana in the Greenville, Greer, or greater Upstate area, you need to understand how these cases work, what the prosecution has to prove, and where the defense opportunities lie. Below, we break it all down.
Is Marijuana Legal in South Carolina in 2026?
No. As of 2026, South Carolina has not legalized marijuana. Possessing, growing, selling, or transporting any amount of marijuana is a criminal offense in South Carolina. Possession of one ounce or less is classified as a misdemeanor punishable by up to 30 days in jail or a fine. Larger amounts carry significantly harsher penalties.
This matters for DUI cases because marijuana possession is illegal on its own, meaning that if officers find marijuana in your vehicle during a traffic stop, you could face both a DUI charge and a separate drug possession charge. Two charges, two sets of penalties, and a much more complicated legal situation.
Can You Get a DUI for Marijuana in South Carolina?
Absolutely. South Carolina's DUI statute (S.C. Code § 56-5-2930) makes it unlawful to operate a motor vehicle while "under the influence of any other drug or a combination of drugs" when your faculties to drive are "materially and appreciably impaired." Marijuana falls squarely under that language.
There is no separate "marijuana DUI" law. Whether you consumed alcohol, marijuana, prescription medication, or a combination, the charge is the same: DUI. And the penalties are the same as well.
Here's the critical distinction from alcohol DUI cases, though: For alcohol, a BAC of .08 or higher automatically creates a legal inference of impairment. No such threshold exists for THC. The prosecution must prove that marijuana materially and appreciably impaired your ability to drive, and proving impairment from THC is far more difficult than proving it from alcohol.
How Does Law Enforcement Test for Marijuana Impairment?
Since there's no breathalyzer for marijuana, law enforcement relies on a different playbook for marijuana DUI investigations:
Field Sobriety Tests (FSTs): Officers may ask you to perform standardized field sobriety tests like the walk-and-turn, one-leg stand, and horizontal gaze nystagmus (HGN) test. These tests were originally designed to detect alcohol impairment, and their reliability for marijuana impairment is widely questioned by defense attorneys and toxicology experts.
Drug Recognition Expert (DRE) Evaluation: South Carolina officers trained as Drug Recognition Experts may conduct a 12-step evaluation protocol that looks for physical signs of drug impairment, including pupil dilation, muscle tone, vital signs, and behavioral indicators. While DRE evaluations carry weight in court, they are inherently subjective and vulnerable to challenge.
Urine Testing: Officers may request a urine sample. However, THC metabolites can remain detectable in urine for days or even weeks after use, long after any impairing effects have worn off. A positive THC test does not prove you were impaired at the time you were driving, and an experienced DUI defense attorney will aggressively challenge this evidence.
Each of these testing methods has weaknesses that a skilled drug defense attorney can exploit in your defense. The science on marijuana impairment is far less settled than the science on alcohol impairment, and that uncertainty works in the defendant's favor.
Penalties for a Marijuana DUI in South Carolina
Because marijuana DUI falls under the same statute as alcohol DUI, the penalties mirror each other based on the number of prior offenses:
First Offense DUI
- Jail time: 48 hours to 30 days (or 48 hours of community service as an alternative)
- Fine: $400 to $1,000
- Six months of the Ignition Interlock Device
- Mandatory enrollment in the Alcohol and Drug Safety Action Program (ADSAP)
Second Offense DUI
- Jail time: 5 days to 1 year
- Fine: $2,100 to $5,100
- Two years of Ignition Interlock Device
- Mandatory ADSAP enrollment
Third Offense DUI
- Jail time: 60 days to 3 years
- Fine: $3,800 to $6,300
- Three to four years of Ignition Interlock Device
- Mandatory ADSAP enrollment
Fourth Offense DUI
- Jail time: 1 year to 5 years
- Five years of Ignition Interlock Device
- Mandatory ADSAP enrollment
Remember, if marijuana was found in your vehicle, the separate possession charge carries its own penalties on top of the DUI consequences.
Defenses Against a Marijuana DUI Charge
Marijuana DUI cases are more defensible than most people realize. Without a per se THC threshold, the entire case rests on the prosecution's ability to prove impairment, and that burden is steep. Common defense strategies include:
Challenging the traffic stop itself: If the officer lacked reasonable suspicion or probable cause to pull you over, any evidence collected after the stop may be suppressed.
Attacking field sobriety test results: FSTs are unreliable indicators of marijuana impairment. Medical conditions, fatigue, nervousness, uneven road surfaces, and even footwear can affect the tests.
Questioning urine test reliability: A positive THC test proves prior use — not current impairment. THC metabolites linger in the body for days or weeks. Chain-of-custody issues and testing lab errors can also undermine results.
Presenting alternative explanations: Bloodshot eyes, slow speech, or an unusual odor can result from allergies, fatigue, legal CBD use, or other entirely innocent factors.
A DUI lawyer in Greenville, SC like John Newkirk who understands both the law and the science can dissect the prosecution's case and identify every available angle for your defense.
Need a DUI Lawyer for a Marijuana DUI Case?
If you've been charged with Marijuana DUI charges, your case is uniquely complex. That complexity creates real opportunities for an experienced defense attorney...but only if you have someone in your corner who knows where to look...
John Newkirk has defended DUI and drug cases across Greenville, Greer, and the Upstate for years. He understands South Carolina DUI law inside and out, knows how to challenge the prosecution's evidence, and fights aggressively to protect his clients' freedom and future. If you're facing a marijuana DUI charge, don't do it alone. The decisions you make right now matter! Don't wait —talk to a lawyer today!
