{"id":286722,"date":"2016-10-14T16:12:20","date_gmt":"2016-10-14T21:12:20","guid":{"rendered":"https:\/\/content.findlaw-admin.com\/ability-law\/dui\/charges\/metabolite-dui-driving-with-a-measurable-controlled-substance.html"},"modified":"2026-04-02T13:41:54","modified_gmt":"2026-04-02T18:41:54","slug":"metabolite-dui-driving-with-a-measurable-controlled-substance","status":"publish","type":"page","link":"https:\/\/www.findlaw.com\/dui\/charges\/metabolite-dui-driving-with-a-measurable-controlled-substance.html","title":{"rendered":"Metabolite DUI: Driving With a Measurable Controlled Substance"},"content":{"rendered":"\n
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Metabolite DUI: Driving With a Measurable Controlled Substance<\/h1>\n\n
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\n By Hannah Hilst<\/a> | Legally reviewed by Meagan Neil, Esq.<\/a>\n | Last reviewed\n
\n \n <\/i>\n Legally Reviewed\n <\/summary>\n\n
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This article has been written and reviewed for legal accuracy, clarity, and style by FindLaw\u2019s team of legal writers and attorneys<\/a> and in accordance with our editorial standards<\/a>.<\/em><\/p>\n\n <\/div>\n <\/details>\n\n

\n \n <\/i>\n Fact-Checked\n <\/summary>\n\n
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The last updated date refers to the last time this article was reviewed by FindLaw or one of our contributing authors<\/a>. We make every effort to keep our articles updated. For information regarding a specific legal issue affecting you, please contact an attorney in your area<\/a>.<\/em><\/p>\n\n <\/div>\n <\/details>\n<\/section>\n\n\n

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When police gather evidence for a\u00a0driving under the influence<\/span> charge\u00a0(DUI<\/span>), they look for the byproducts of the ingested substance called metabolites<\/span>. If they find a measurable amount of a <\/span>controlled substance<\/span>, they may arrest the driver for intoxicated driving. There are a few ways to challenge DUI<\/span> metabolite<\/span> charges<\/span> and test results.<\/p>\n\n <\/div>\n\n\n\n

Police test for blood-alcohol concentration (BAC<\/span>) at a typical DUI<\/span>\/DWI<\/span> stop. These sobriety tests<\/span> aren\u2019t perfect, but they\u2019re relatively accurate. But alcohol is just one of the countless substances that can cause impairment<\/span>.<\/p>\n

Others, such as marijuana, heroin, and even\u00a0legal prescription painkillers<\/a>, are more difficult to measure. Many of these drugs stay in the system much longer than alcohol \u2014 long after they stop causing impairment<\/span>. This challenges police officers to determine accurate impairment<\/span> levels at a precise time.<\/p>\n

This article discusses drug-related DUIs<\/span> and metabolites<\/span>. It also addresses driving under the influence<\/span> of marijuana. Finally, it discusses state approaches to measuring controlled substance<\/span> use by drivers.<\/p>\n

If you\u2019re up against DUI<\/span> charges<\/span>, get more detailed advice for your case. Ask for a DUI<\/span> defense<\/span> lawyer\u2019s<\/a> perspective to better understand your options. They can explain how to fight the charges<\/a> or minimize the consequences.<\/p>\n

What Are Metabolites<\/span>?<\/h2>\n

Metabolites<\/span> are chemicals that appear in a person\u2019s body<\/span> as it processes a substance. There are many different types of metabolites<\/span>. In the context of DUI<\/span> laws<\/span>, metabolites<\/span> generally refer to the byproducts of alcohol, prescription drugs<\/span>, and illegal drugs<\/span>.<\/p>\n

Sometimes, these metabolites<\/span> can be present in the body for a long time after you use a substance. They could still be present when you\u2019re sober or when the main effects of a drug have worn off.<\/p>\n

Police must base DUI<\/span> charges<\/span> on evidence<\/a>. Metabolites<\/span> offer proof that the offender metabolized a certain amount of a given substance at a given time.<\/p>\n

Metabolites<\/span> in Alcohol DUI<\/span> Cases<\/span><\/h3>\n

Breathalyzer and chemical tests<\/span> don\u2019t directly measure the amount of alcohol in your bloodstream. Instead, they measure the concentration of the metabolites<\/span>\u00a0alcohol dehydrogenase<\/a>\u00a0(ADH) and aldehyde dehydrogenase (ALDH).<\/p>\n

Your body metabolizes\u00a0alcohol<\/a>\u00a0at a relatively fast rate of roughly .016 percent (or one average alcoholic drink) per hour. As a result, this measurement gives a reasonably accurate snapshot of a driver\u2019s BAC<\/span> during a motor vehicle<\/span> traffic stop.<\/p>\n

Metabolites<\/span> in Drug-Related DUI<\/span> Cases<\/span><\/h3>\n

In contrast to alcohol,\u00a0legal or illegal drugs<\/span><\/a> work differently. They break down into their own unique metabolites<\/span>. There are ways to detect and accurately measure those metabolites<\/span>.<\/p>\n

As a result, many states have a \u201czero tolerance<\/span>\u201d or\u00a0per se<\/span>\u00a0approach<\/a> to non-alcohol DUI<\/span> charges<\/span>. This means a motorist who isn\u2019t impaired at the time of a traffic stop may still be guilty of driving under the <\/span>influence<\/span> of drugs<\/span>. This applies if the metabolites<\/span> are present at the time of the stop. State law may limit metabolites<\/span> either above a certain level or at any detectable level.<\/p>\n

Testing for Marijuana DUIs<\/span><\/h2>\n

Marijuana, also known as cannabis<\/span>, is the second most common substance in DUI<\/span> cases<\/span>. But it is much more challenging to measure<\/a> in the context of a DUI<\/span> investigation than alcohol.<\/p>\n

Marijuana use is legal in some states<\/a>, but \u201cstoned driving\u201d is illegal in every state. States that allow recreational or medical marijuana still need to protect public safety. Many states will arrest DUI<\/span> suspects who have any measurable level of THC<\/span> (the psychoactive component of marijuana) in their blood. The limit will depend on state DUI<\/span> laws<\/span><\/a>.<\/p>\n

How Long Does Marijuana Stay in the Body?<\/h3>\n

Marijuana metabolites<\/span> remain\u00a0in the bloodstream (as measured in urine) for roughly one week<\/a> after ingestion. The specific timing can vary based on your metabolism and frequency of cannabis<\/span> use. The duration is long even though the high from marijuana may only last a few hours.<\/p>\n

The timing can make it difficult to prove whether you were sober or high when police stopped you. That\u2019s why the presence of marijuana metabolites<\/span> in a urinalysis needs supporting evidence from a drug recognition expert.<\/p>\n

Other evidence of intoxication could consist of behavior such as:<\/p>\n