The drug test run in federal workplace programs in the United States does not look for kratom. Its panel, published by the Department of Health and Human Services, names sixteen drugs and metabolites, and mitragynine, the main kratom alkaloid, is not one of them. A laboratory can find kratom, but only with a test built to look for it.
That is the short answer, and it is accurate. It is also incomplete in three ways that matter: what an employer other than a federal agency chooses to test for, what a dedicated test can see and for how long, and what else is sometimes in a product sold as kratom.
This page is about what assays detect. It is not about passing one, and it will not tell you when any particular test would come back negative. The studies that exist cannot answer that, as the section on detection times explains.
What the federal panel looks for
The rules for drug testing of federal employees are the Mandatory Guidelines for Federal Workplace Drug Testing Programs. The urine version in force today was published on 12 October 2023 (88 FR 70768) and took effect on 1 February 2024. The list of what is tested sits in a separate document, the authorized testing panel, which HHS publishes in the Federal Register.
The current panel took effect on 7 July 2025. HHS republished it on 13 March 2026 with no change to the substances or the cutoffs. For urine it covers:
- Marijuana, by its metabolite THC-carboxylic acid
- Cocaine, by its metabolite benzoylecgonine
- Opioids: codeine, morphine, hydrocodone, hydromorphone, oxycodone, oxymorphone, 6-acetylmorphine (a heroin marker), and since July 2025 fentanyl and norfentanyl
- Phencyclidine (PCP)
- Amphetamines: amphetamine, methamphetamine, MDMA and MDA
Informal names for tests like this vary. The document that decides what a federal laboratory looks for is the HHS panel, and mitragynine, 7-hydroxymitragynine and kratom do not appear in it. Neither does tramadol.
There is a legal reason as well as a practical one. Section 3.1 of the guidelines requires testing for marijuana and cocaine and authorises the other Schedule I or II drugs on the panel. Section 3.2 lets an agency add a Schedule I or II drug outside the panel case by case, after an accident or on reasonable suspicion; routine testing for any other drug class needs a written petition approved by the Secretary of Health and Human Services. The case-by-case route turns on a drug’s federal schedule. As of 29 October 2026, kratom leaf and mitragynine are not in any federal schedule. Neither is 7-hydroxymitragynine: the Drug Enforcement Administration’s notice of 14 October 2026 is a statement of intent, and it says the order will be published on or after 13 November 2026. Three laboratory-made relatives (mitragynine pseudoindoxyl, MGM-15 and MGM-16) have been in Schedule I under a temporary order since 26 August 2026. Two DEA notices of 14 October 2026 would replace that order, and under them mitragynine pseudoindoxyl would be controlled only above the same threshold as 7-hydroxymitragynine.
Three limits on what this tells you. First, the guidelines bind federal agency programs. Transportation employers test under separate Department of Transportation rules, which we have not read for this page, and private employers, clinics, courts and treatment programmes may use other panels; we have not surveyed what those contain. Second, section 3.3(b) says the guidelines are not intended to stop an agency “specifically authorized by law” from testing for additional classes of drugs. Third, HHS published proposed revisions to the urine guidelines on 29 October 2026 (91 FR 68398), open for comment until 28 December 2026. We read the proposal. It would publish the panel only when it changes rather than every year, and it rewrites section 3.2, keeping additional testing to panel drugs and other Schedule I or II drugs. It does not mention kratom or mitragynine, and nothing in it is in force.
How a screening test decides what it sees
Most drug tests are two tests. The first, the initial test, is usually an immunoassay: a chemical reaction built around an antibody that binds one target drug or a family of closely related ones. It is fast and cheap, and it answers only the question it was built to ask. A sample that screens positive goes on to a confirmatory test, normally mass spectrometry, which identifies a molecule by its mass and the way it breaks apart.
The HHS panel itself shows how narrow an antibody can be. Where one immunoassay is used for a group of drugs, its footnotes require it to react at least 80 percent as strongly to the other members of the group as to the one it was calibrated on, or else a separate assay must be used. A fentanyl immunoassay must react at least 5 percent as strongly to norfentanyl, fentanyl’s own breakdown product. An antibody reacts to what it was built and checked against, and nothing in the federal panel is built or checked against a kratom alkaloid. Whether any particular commercial assay reacts to one by chance is a separate question, taken up below.
Two studies show the result in practice, and neither was a test of kratom specifically.
- One patient, Germany, 2010. Arndt and colleagues tested the urine of a woman in a rehabilitation programme who had been drinking infusions of a product sold as “Krypton”. Immunoassays for amphetamines, barbiturates, benzodiazepines, cocaine, buprenorphine, methadone, opiates, oxycodone and cannabis were all negative. Mass spectrometry found five kratom alkaloids. We read the abstract; the full text is behind a paywall.
- Four hundred emergency patients, New York. Rosano and colleagues (2025) ran the hospital’s usual immunoassay screen, covering eight drug classes, alongside a mass-spectrometry panel of 116 drugs and metabolites that included mitragynine and 7-hydroxymitragynine. The immunoassay missed 890 of the 1,350 drug findings the mass-spectrometry panel made, because of high cutoffs or because the drug was outside its scope. Mitragynine was found in one patient, by the mass-spectrometry panel.
Immunoassays aimed at mitragynine do exist, but in the research literature rather than on the federal panel. One, described by Lee and colleagues (2020), detected mitragynine down to 15 nanograms per millilitre (ng/mL) and reacted with several of its metabolites, while reacting less than 0.01 percent to codeine, morphine, methadone, amphetamine and cocaine. That is a statement about that antibody, not about the immunoassays a workplace uses. We read the abstract.
False positives: what the literature does and does not show
“False positive” is used for two different things, and they need separating.
A kratom user testing positive for something else. We searched Europe PMC on 29 October
2026 with (kratom OR mitragynine) AND (TITLE_ABS:"immunoassay" OR TITLE_ABS:"false positive" OR TITLE_ABS:"false-positive" OR TITLE_ABS:"cross-reactivity" OR TITLE_ABS:"cross-reactive" OR TITLE_ABS:"cross-reacts" OR TITLE_ABS:"urine drug screen" OR TITLE_ABS:"urine drug test"), which
returned 22 records, and read their abstracts. A broader search, (kratom OR mitragynine OR "Mitragyna speciosa") AND (immunoassay OR "false positive" OR "false-positive" OR "cross-reactivity" OR "cross reactivity" OR "drug screen" OR "drug screening" OR "drug test" OR "drug testing" OR urine OR "LC-MS/MS" OR "detection window") across all fields, returned 647,
whose titles we screened. Both searched titles and abstracts as indexed, not full texts. We did not find a peer-reviewed report of kratom
or mitragynine producing a false positive on a standard opiate, methadone or other panel
immunoassay. That is the result of our search, not proof that it cannot happen: immunoassays
differ by manufacturer, and an unpublished case would not appear. If you have read that kratom
triggers a positive for opiates or methadone, we could not find the analytical paper behind it.
A mass-spectrometry result that names the wrong molecule. This one is documented. Kratom leaves contain mitragynine and three other alkaloids with the same formula and the same mass, differing only in the three-dimensional arrangement of their atoms. A method that does not separate them reports their combined signal as “mitragynine”.
Helander and Rylski (2023) found exactly that at the Karolinska University Laboratory in Stockholm. Its routine method could not separate mitragynine from two of the others. When they re-tested 29 urine samples that had been reported positive for mitragynine above the laboratory’s 100 microgram per litre cutoff, all 29 did contain mitragynine, but in eight of them (28 percent) mitragynine on its own was below the cutoff. The other alkaloids had carried those samples over the line. This matters in Sweden because mitragynine is a classified narcotic there and its three look-alikes are not. In most samples the most abundant of the four was speciociliatine, not mitragynine.
Papsun and colleagues (2019), reporting 1,001 blood samples positive for mitragynine at their forensic toxicology laboratory over 27 months, made the same point about numbers: concentrations in the published literature may be falsely high where a method did not resolve mitragynine from these related compounds. We read the abstract.
The reverse error exists too. A negative screen does not mean nothing was there. In the German case above, a test strip for tramadol and its metabolites was negative at its cutoff of 10 milligrams per litre for O-desmethyltramadol. Mass spectrometry then found about 9 milligrams per litre of O-desmethyltramadol in the same urine. The strip was not wrong. The amount was just under the line it was built to draw.
What a dedicated laboratory test looks for
A test built for kratom is usually LC-MS/MS (liquid chromatography with tandem mass spectrometry): the sample is separated over time in a column, then each compound is identified by its mass and its fragments.
What it targets varies by laboratory, and that choice changes what it can find.
- Le and colleagues (2012) published a validated urine method. It quantifies mitragynine from 1 to 500 ng/mL and also looks for two of its metabolites and for 7-hydroxymitragynine. We read the abstract.
- Basiliere and Kerrigan (2020) found that two of mitragynine’s look-alike alkaloids, speciociliatine and speciogynine, often exceeded mitragynine itself in urine, and proposed them as additional markers of kratom use. In urine that had not been chemically treated, a metabolite, 9-O-demethylmitragynine, was present in 75 percent of cases and 7-hydroxymitragynine in 63 percent. We read the abstract.
- Very little leaves the body unchanged. In the Thai study described below, only 0.14 percent of the mitragynine dose was excreted unchanged in urine. Even so, Basiliere and Kerrigan found mitragynine, its look-alikes and its metabolites abundant enough in urine that an extra processing step to free bound metabolites was not needed.
Thresholds are not standard. Helander and Rylski note that Sweden has no nationally agreed cutoff for mitragynine; their laboratory reported a positive at 100 micrograms per litre, which is 100 ng/mL. The New York emergency panel listed a detection limit of 2 ng/mL for mitragynine and for 7-hydroxymitragynine. A reporting cutoff and a detection limit are not the same kind of threshold, but the gap shows how differently two working laboratories can be set up. There is no federal cutoff, because there is no federal analyte.
How long the studies could measure it
We found three human studies that measured how long kratom alkaloids stay measurable. All are small. None set out to find a detection window for a workplace test, and the figures cannot be turned into a prediction for any individual.
- Trakulsrichai and colleagues (2015), Thailand. Ten men who used kratom regularly drank kratom tea daily for a week, then a measured dose. In nine of them the terminal half-life of mitragynine, the time for the blood level to halve in the final phase of elimination, was 23.2 hours on average, with a standard deviation of 16.1 hours. That spread is nearly as large as the average. Blood was sampled for only 24 hours, and the Tanna study below pointed out that a half-life close to the length of the sampling period is hard to estimate reliably.
- Tanna and colleagues (2022), United States, funded by the National Institutes of Health. Six healthy adults who had used kratom before drank one tea made from 2 grams of leaf powder; five completed the study. Every alkaloid the team measured was still quantifiable in urine at 120 hours, five days, the last collection. Mitragynine was quantifiable in blood to at least 96 hours, and 7-hydroxymitragynine to 24 hours. Five days is when sampling stopped, not when the alkaloids disappeared. The method’s lower limit of quantitation was 0.23 nanomoles per litre, under 0.1 ng/mL for mitragynine, far below a 100 ng/mL clinical cutoff.
- Huestis and colleagues (2024) gave single and repeated doses of leaf powder in capsules to cohorts of twelve or thirteen adults and measured blood, not urine. After the highest single dose, the median last measurable time for mitragynine was 120 hours; during repeated dosing it reached medians of 168 and 169 hours in the two highest-dose cohorts. Measured half-lives rose with dose. The study was paid for by the company whose kratom product was tested, and all four authors were paid consultants to that company, one of them also employed by a pharmaceutical company; two were also consultants to the American Kratom Association, an industry body. We report it because it is the only one of the three to measure levels across a 15-day course of daily doses, and no finding on this page rests on it alone.
What this adds up to: in small studies with very sensitive research methods, kratom alkaloids were measurable for days after a dose, and longer after repeated doses. How long a particular test would find them depends on what it targets, where its cutoff sits, how much was taken and for how long, and individual differences that the studies show are large. We do not know a number, and the three studies we found do not supply one.
What else may be in the product
Kratom alkaloids are not on the federal panel, and neither are the substances below. Each is here for the reason given under it, and each has a legal status different from kratom’s.
O-desmethyltramadol is a synthetic opioid and the active metabolite of the painkiller tramadol. It was the likely added ingredient in the German “Krypton” case above, where the authors wrote that its origin was unclear and that a spiked product could explain the findings, and the DEA describes fatal Swedish cases involving the same mixture. The DEA’s order of 12 August 2026 placed it temporarily in Schedule I, and the order records that it “was found to be mixed with the kratom plant”, established by testing packaging and by finding both it and mitragynine in people’s toxicology results. Being in Schedule I makes it a drug a federal agency may add to a test case by case. It is not on the standard panel. Our report on the O-desmethyltramadol scheduling order covers what the order does.
Concentrated 7-hydroxymitragynine and mitragynine pseudoindoxyl are the subject of the DEA’s current notice, and mitragynine pseudoindoxyl is already in Schedule I. Neither is on the HHS panel. A laboratory method has to be built to look for them, and as the Swedish work shows, has to separate them from look-alike compounds to name them correctly.
Tianeptine is not a kratom alkaloid, and we have no source showing it in kratom products. It belongs on this page because some state laws put it beside kratom: as our Maryland page records, Maryland’s 2026 act names kratom, tianeptine and phenibut products together. As of 29 October 2026 tianeptine is not federally scheduled. The DEA proposed placing it in Schedule I on 8 July 2026, the comment period closed on 7 August, and we found no final rule in the Federal Register. Utah’s state Schedule I already lists it, as our Utah page records. The FDA’s position, in a May 2025 letter to health professionals, is that tianeptine “may not be identified in routine drug screening panels”.
What a person did not know was in a product is the hazard here, more than the test. A label that says kratom tells you nothing reliable about whether it contains a synthetic opioid. Our guide to what testing has found in kratom products covers what laboratories have found.
The honest position
Reasonably supported. The federal workplace panel does not include mitragynine or any kratom alkaloid. The route by which a federal agency adds a drug case by case is limited to Schedule I or II drugs, which kratom and mitragynine are not. Standard immunoassays were negative in the one published kratom case we found that used them, and in a 400-patient study only mass spectrometry found mitragynine. One research LC-MS/MS method, with a very low quantitation limit, found kratom alkaloids in the urine of five participants for at least five days after a single small dose. Mass-spectrometry methods that do not separate mitragynine from its look-alikes can overstate it.
Not established. Whether kratom causes false positives on any commercial immunoassay: we found no report, which is not the same as none existing. What a detection window is for any real-world test, cutoff or pattern of use. What panels private employers, clinics and courts use.
This page is not legal or medical advice. It describes what tests are built to detect, from the documents that define them and the studies that measured them.