KRA on a drug screen stands for kratom, a plant-based substance derived from the leaves of a Southeast Asian tree. If you see KRA listed on your drug test results, the lab specifically tested for kratom’s primary active compound, mitragynine, and its metabolites. Kratom does not show up on standard drug panels. It requires a separate, specialized test, which means someone deliberately ordered it.
Why Kratom Has Its Own Test Panel
Standard drug screens, like the common 5-panel or 10-panel tests, check for substances such as opioids, amphetamines, benzodiazepines, cocaine, and marijuana. Kratom is not included in any of these standard panels. Its chemical structure is different enough from traditional opioids that it won’t trigger a positive result on a routine opiate immunoassay.
However, kratom does interact with opioid receptors in the brain, which is why some employers, treatment programs, and courts have started adding it as a separate line item. When you see KRA on your results, it means the ordering party paid for an expanded or custom panel that specifically includes kratom testing.
How the Test Works
Kratom testing uses a two-step process. The initial screen is an immunoassay, a quick antibody-based test that flags samples above a threshold of 5.0 ng/mL for mitragynine. If that first screen comes back positive, the lab runs a confirmatory test using liquid chromatography with tandem mass spectrometry (LC-MS/MS), a far more precise method that identifies the exact compound present. The confirmation threshold drops to 1.0 ng/mL, according to Labcorp’s published testing methodology.
This two-step approach matters because immunoassays can produce false positives. A confirmed result through LC-MS/MS is considered definitive. If your result says “positive” but only the initial screen was run, you can request confirmatory testing.
How Long Kratom Stays Detectable
Mitragynine, the main active compound in kratom, has a relatively short half-life of about 3 hours. That means half the substance clears your bloodstream every 3 hours after your last dose. For most people, this translates to a urine detection window of roughly 5 to 7 days, though heavy or long-term use can extend that. Factors like body fat percentage, hydration, liver function, and how frequently you’ve used kratom all influence how quickly it clears.
Because the screening threshold is extremely low at 5.0 ng/mL, even small amounts can trigger a positive result days after use.
Kratom and False Positives on Other Panels
One complication worth knowing about: kratom can cause a false positive for methadone on certain drug screens. Research published in the American Journal of Clinical Pathology found that a kratom metabolite cross-reacts with at least one common methadone metabolite immunoassay, triggering a positive result even though no methadone was used. If you’ve used kratom and your drug screen unexpectedly shows a positive for methadone, this cross-reactivity is a likely explanation, and confirmatory testing would clear it up.
Who Orders Kratom Testing
Kratom testing is becoming more common in specific settings. Substance abuse treatment programs frequently add it to their panels because of its opioid-like effects. Some pain management clinics include it to monitor whether patients are supplementing their prescriptions with kratom. Certain probation and parole departments have also begun testing for it, particularly in states where kratom use is a concern.
Routine pre-employment drug screens at most companies still do not include kratom. If KRA appeared on your results, it was almost certainly ordered intentionally by whoever requested the test, whether that’s a treatment provider, employer with a specialized panel, or a court.
Kratom’s Legal and Regulatory Status
Kratom is not a federally scheduled substance, which means it is not illegal under federal law. However, it occupies a complicated regulatory space. The FDA has not approved any drug products or dietary supplements containing kratom. The agency considers kratom an adulterated substance when sold as a dietary supplement or food additive and has issued public warnings about risks including liver toxicity, seizures, and substance use disorder.
Several states and municipalities have banned kratom outright, while others have passed consumer protection laws that regulate its sale without banning it. Whether a positive KRA result carries consequences for you depends entirely on the context: a workplace policy, a treatment agreement, or a legal requirement. The legal status in your specific state and the rules of whoever ordered the test are what determine what a positive result means for your situation.
What a Positive KRA Result Means
A positive KRA result simply confirms that mitragynine was detected in your urine above the testing threshold. It does not measure impairment, indicate how much you used, or specify when you last used it. Like most urine drug tests, it’s a yes-or-no answer to the question of recent exposure.
If you believe the result is inaccurate, you have the right to request the confirmatory LC-MS/MS test, which will either verify or rule out the presence of kratom metabolites with high precision. False positives on the initial immunoassay screen are possible, though less common for kratom than for some other substances, because the test is designed specifically for mitragynine rather than relying on cross-reactivity with a broader drug class.