Understanding Kratom and Its Legal Status
Kratom, scientifically known as Mitragyna speciosa, is a tropical tree from the coffee family, native to Southeast Asia [1.2.3]. Its leaves contain psychoactive alkaloids, primarily mitragynine and 7-hydroxymitragynine [1.11.1]. Traditionally, people have used it for its stimulant effects at low doses and its opioid-like sedative and pain-relieving effects at higher doses [1.4.1]. In the United States, an estimated 1.7 million people aged 12 and over used kratom in 2021 [1.8.2]. As of 2025, kratom is not a federally controlled substance, though the FDA has not approved it for any medical use and warns against its consumption due to risks of liver toxicity, seizures, and addiction [1.10.1, 1.10.4]. The legal status varies significantly by state, with six states (Alabama, Arkansas, Indiana, Rhode Island, Vermont, and Wisconsin) having complete bans as of July 2025 [1.10.1, 1.10.2]. Many other states and local jurisdictions have regulations concerning its sale, such as age restrictions [1.10.2].
How Standard Drug Tests Work
The most common employment drug screenings are 5-panel and 10-panel tests. These tests are designed to detect specific, commonly abused substances by identifying their metabolites in a sample of urine, blood, or hair [1.2.5, 1.3.3].
- 5-Panel Test: Typically screens for THC (marijuana), cocaine, amphetamines, opiates (like heroin, codeine, and morphine), and phencyclidine (PCP) [1.3.2, 1.3.3].
- 10-Panel Test: Includes the substances from the 5-panel test plus barbiturates, benzodiazepines, methaqualone, methadone, and propoxyphene [1.2.2]. Crucially, these standard panels are not designed to look for kratom's unique alkaloids [1.2.4, 1.6.5]. Therefore, kratom use will not cause a positive result on these common tests [1.2.2].
Does Kratom Show Up as an Opioid?
No, kratom does not show up as an opioid on a standard drug test [1.6.1]. The alkaloids in kratom, mitragynine and 7-hydroxymitragynine, are structurally distinct from the opiate molecules that these tests are calibrated to detect [1.4.1]. While kratom's alkaloids do bind to mu-opioid receptors in the brain, which is responsible for its opioid-like effects, their chemical structure is different enough to not trigger a positive result for opiates [1.5.1, 1.4.1].
The Risk of False Positives
While kratom doesn't register as a traditional opioid, there is evidence suggesting it can, in some cases, cause a false positive for other substances. Specifically, studies have shown that a kratom metabolite can cause false-positive results for methadone on certain immunoassay-based urine drug screens [1.9.1, 1.9.4]. In such an event, a confirmatory test, such as liquid chromatography-mass spectrometry (LC-MS), would be performed. This more precise test would be able to distinguish kratom metabolites from methadone, clarifying the initial result [1.9.2].
Specialized Kratom Drug Testing
Although standard tests won't find it, specialized tests that specifically target kratom's alkaloids are available [1.6.4, 1.6.5]. These tests are not routinely used by most employers but may be ordered in specific situations, such as by law enforcement, in substance abuse treatment programs, or for certain government jobs [1.2.2, 1.6.4]. These advanced tests can detect mitragynine and 7-hydroxymitragynine in urine, blood, and hair [1.6.5].
- Urine Tests: Can detect kratom for up to a week, or even nine days for heavy users [1.7.1, 1.7.2].
- Blood Tests: Have a shorter detection window, typically 1 to 3 days after use [1.7.1, 1.7.2].
- Hair Follicle Tests: Can detect substance use for up to 90 days, though they are not commonly used for kratom [1.6.3, 1.6.5].
The detection window is influenced by several factors, including the user's metabolism, body fat percentage (mitragynine is fat-soluble), age, and the frequency and dosage of kratom used [1.2.3, 1.7.2].
Kratom vs. Traditional Opioids: A Pharmacological Comparison
While both interact with opioid receptors, kratom's alkaloids and traditional opioids differ significantly in their mechanism of action and effects [1.4.1].
| Feature | Kratom Alkaloids (Mitragynine) | Traditional Opioids (e.g., Morphine) |
|---|---|---|
| Receptor Interaction | Partial agonist at mu-opioid receptors; also interacts with other receptors like serotonin and dopamine [1.5.1, 1.5.5]. | Full agonist at mu-opioid receptors [1.5.5]. |
| β-Arrestin Pathway | Does not significantly recruit the β-arrestin pathway [1.4.1]. This pathway is linked to severe side effects like respiratory depression [1.4.1, 1.4.5]. | Strongly recruits the β-arrestin pathway, leading to a higher risk of respiratory depression and constipation [1.4.5]. |
| Risk of Respiratory Depression | Significantly lower risk compared to traditional opioids [1.4.3]. | High risk, a common cause of overdose-related death [1.4.1]. |
| Addiction Potential | Can lead to dependence and withdrawal symptoms similar to opioids [1.5.4, 1.5.5]. | High potential for addiction and severe withdrawal [1.3.2]. |
| Legal Status (U.S.) | Federally legal but banned/regulated in some states and cities as of 2025 [1.10.1]. Not FDA-approved [1.8.2]. | Many are Schedule I or II controlled substances; available by prescription [1.3.4]. |
Conclusion
To summarize, kratom will not show up as an opioid on standard 5-panel or 10-panel drug tests because these screens are not designed to detect its unique alkaloids [1.2.4]. However, specialized tests that specifically look for mitragynine and its metabolites do exist and can be used when kratom use is suspected [1.6.5]. While rare, false positives for methadone have been reported, which require more advanced confirmatory testing to resolve [1.9.1]. Users should be aware of the legal status of kratom in their location and understand that while it may not appear on a routine test, its use is not without health risks and the potential for detection through specific methods [1.10.2, 1.10.4].
For more information on the potential risks and lack of regulation, you can visit the FDA's public health focus page on kratom [1.8.2].
