Mitragynine Toxicity: What It Is and What the Data Show

Mitragynine toxicity is the harm clinicians describe when someone has taken too much kratom, or has taken it in a bad combination with other substances. Mitragynine is kratom's main alkaloid. StatPearls, a peer-reviewed clinical reference, lists signs that run from agitation and a fast heart rate to seizures and liver injury, and says kratom toxicity has in some cases been linked to death. Kratom toxicity and mitragynine poisoning are the same subject under other names. We sell concentrated kratom extracts, every one of which contains mitragynine, so this page is about our own products too. It gives no amounts to take or to avoid.

The short answer: what is mitragynine toxicity

What it is. Harm from too much kratom, or from kratom with other substances. StatPearls warns that "At higher doses, kratom toxicity can mimic an opioid toxidrome", meaning it can look like opioid poisoning.

How often. No source we read gives a rate per person who uses kratom. Poison centers count calls, not people harmed, and death records that find kratom often cannot say what part it played.

Where the worst outcomes cluster. In combinations. Reports involving other substances ended in hospital more often, and most deaths in the data involved other substances. Reports of kratom alone had serious outcomes too.

Mitragynine poisoning and kratom toxicity: what clinicians mean

StatPearls' clinical review of kratom, a chapter for clinicians last updated on September 14, 2026, lists "a range of toxicities and adverse events associated with kratom use, including hepatotoxicity, seizures, coma, lung injury, kidney injury, and cardiotoxicity." Its reference for that sentence is a study in rats, so read the list as a catalog, not a measure of how often.

It is frank about treatment: kratom use, toxicity and withdrawal "require further research to establish definitive management practices."

The National Institute on Drug Abuse, on its kratom page dated March 2026, says "Rare but serious effects have been reported in people who use kratom, including psychiatric, cardiovascular, gastrointestinal and respiratory problems." The table sets it beside two other sources.

The Czech authors concluded that "Kratom overdose toxidrome is variable". Ten patients are ten cases, not a rate. For the milder end of the range, our page on what too much feels like, and how the sources tell it from withdrawal goes through the record.

What poison center reports count, and what they do not

A 2026 report in CDC's MMWR, by researchers at the University of Virginia's Division of Medical Toxicology and colleagues, published on March 26, 2026, counted "14,449 kratom exposure reports" among people aged 12 and older from 2015 through 2025. The yearly count rose from 258 in 2015 to "the record high 3,434 reports in 2025", an increase of about 1,200 percent.

Read the unit before the number. The coding manual behind the data "defines an exposure report as actual or suspected contact with a substance that prompted a consultation with a poison center, regardless of toxicity or clinical manifestations." A report is a consultation, not a person harmed, and a rise in reports is not a measured rise in harm per person who uses kratom. The authors add that the data are "voluntary, self-reported", which might undercount milder events, and include repeat callers.

What the reports do show is where serious outcomes gather. Reports involving other substances were 38 percent of the total, and in every year a larger share of them ended in hospital.

Kratom exposure reports to US poison centers, people aged 12 and older, 2015 to 2025 (MMWR, March 26, 2026).

Serious outcomes, in the report's definition, are death, major effects and moderate effects. "Kratom the only substance reported" describes the call, not a toxicology result.

Deaths in the data: detected is not caused

CDC's 2019 review of overdose deaths is the clearest lesson in reading these numbers. It covered 27,338 overdose deaths in up to 27 states from July 2016 to December 2017. Of the people who died, 152, or 0.56 percent, "tested positive for kratom on postmortem toxicology".

A medical examiner or coroner listed kratom as a cause of death for 91 of those 152. For the other 61, by our arithmetic, kratom was found but not listed as a cause. Seven of the 91 had kratom as the only substance that tested positive, "although the presence of additional substances cannot be ruled out". "Postmortem toxicology testing detected multiple substances for almost all decedents", and any fentanyl, analogs included, was listed as a cause for 65.1 percent of the kratom-positive deaths. CDC also warned that "Identification of kratom is method-dependent", so its count may be low.

The 2026 poison center report shows the same pattern. Of 233 kratom-associated deaths reported to poison centers from 2015 through 2025, "184 (79%) involved multiple substances", and opioids were reported in 62 percent. The authors wrote that "determining which substance was most related to clinical effects or medical outcome, including death, was not possible." These are deaths among calls to poison centers, not a national death count.

FDA's kratom page, current as of December 2, 2025, gives the agency's reading: "In rare cases, deaths have been associated with kratom use, as confirmed by a medical examiner or toxicology reports. However, in these cases, kratom was usually used in combination with other drugs, and the contribution of kratom in the deaths is unclear."

The phrase itself appears in FDA's adverse event data. In a 2023 FDA Science Forum poster on 2021 reports, medical and toxicology results came back for 10 of 20 death reports, and "Mitragynine toxicity was listed as the sole cause of death in 4 cases (40%), and a contributory factor in the other 6 cases (60%)." The poster cautions that "there is no certainty that a suspected product caused a reaction for any given report". A 2022 narrative review by University of Florida researchers reaches the plain conclusion: "the risk of death due to using kratom alone is challenging to determine."

The liver and other organs

NIH's LiverTox entry on kratom, last updated on April 3, 2020, gives kratom a "Likelihood Score: B (likely cause of clinically apparent liver injury)" and says "Kratom has been linked to rare instances of clinically apparent acute liver injury." The letter grades how likely kratom is to be the cause; "rare" is LiverTox's word for how often.

Onset is "usually within 1 to 8 weeks of starting regular use of kratom powder or tablets, with symptoms of fatigue, nausea, pruritus and dark urine followed by jaundice", and the injury is "typically cholestatic or mixed, and it can be severe". On cause, LiverTox is careful: "The cause of liver injury due to kratom is unknown. It is often used with other agents, including drugs of abuse, and its causative relationship to liver injury in published cases is not always clear." For clinicians, it adds that patients "usually recover once it is discontinued".

NIDA describes a different shape, worth reading beside it: "Case reports do show regular, long-term, kratom use in large amounts may be associated with serious liver problems. These cases appear to occur unpredictably in a small minority of people who use kratom, and it is unclear what role other substances and underlying health conditions may play." Neither gives a safe length of use.

Beyond the liver, the same 2022 review found "Cardiovascular, gastrointestinal, neurological, and psychiatric effects associated with kratom use were especially notable", with heart findings in clinical reports running from palpitations to "cardiac arrest". Its authors are plain about the evidence: "These findings, predominantly from case studies, indicate that some people who use kratom are experiencing adverse events."

Concentrated extracts, including ours

Our own products belong here. New York's health department, in guidance revised in December 2025, warns that "Kratom's toxicity may be worsened when an element of the kratom leaf is concentrated and consumed", and singles out products made extra-strong with the concentrated minor alkaloid. Its guidance for clinicians describes kratom extracts and tinctures as "concentrated liquid or resin forms, which isolate the alkaloids and are often much more potent than whole-leaf or powder products." We sell concentrated liquid extracts.

A label does not settle it. New York's clinicians' page says: "It is unregulated, so customers have no way of knowing if product labeling is accurate or if there are other potentially hazardous contaminants." That covers our labels too. Our page on what a certificate of analysis lists and leaves out explains what ours measure and what they do not.

The 2026 MMWR describes a market moving toward "powders, tablets, gummies, and concentrated energy shots"; our Rush line is concentrated energy shots, with caffeine. Its data could not tell leaf from concentrated products, which limits "conclusions about formulation-specific risks". And New York's clinicians' page says kratom mixed "with other psychoactive ingredients, such as kava or caffeine," complicates "clinical assessment and diagnosis".

The American College of Medical Toxicology's August 2026 position statement, on the concentrated minor alkaloid and other kratom-associated compounds, says products built on the minor alkaloid have been linked to overdose and death, and that the minor alkaloid's toxic dose "remains unknown, and no safe dose can be recommended." Our listings state mitragynine content, and that is not a safety finding in our favor: we found no federal agency that has set a mitragynine limit for extracts.

The one federal alert we found on a liquid kratom extract as a product, FDA's of July 26, 2024, concerned one brand that FDA said "has been linked to serious adverse health effects, including death", on the basis of adverse event reports it was investigating. It is the category we sell.

Mixing kratom with other drugs

In the 2026 MMWR's words: "Severe outcomes were observed among persons who used kratom with other substances: approximately one half required inpatient hospitalization, and 79% of reported kratom-associated deaths involved multiple substances." The substances most often reported with kratom were "ethanol, 22%; opioids, 16%; benzodiazepines, 15%; cannabis and cannabinoids, 12%; and stimulants, 11%", plus antidepressants at 14 percent.

The authors suggest how. Kratom with alcohol, opioids, benzodiazepines, stimulants and antidepressants "might increase risk through additive pharmacodynamic effects on central nervous system pathways and through pharmacokinetic interactions that increase systemic exposure to substances used with kratom". Put simply, effects may stack, and kratom may raise how much of another drug reaches the body. Among its patient-education points, New York's guidance for clinicians lists: "Avoid mixing kratom with other drugs or medications, especially depressants including alcohol, opioids, benzodiazepines and dissociatives."

Controlled evidence in people is thin. The one controlled human interaction study we found, published in Clinical Pharmacology and Therapeutics in 2023, gave 12 healthy adults one low dose of kratom tea with two probe drugs. It found "no effect" on dextromethorphan "but a modest increase" in blood levels of midazolam, and because midazolam's half-life did not change, the authors read that as a sign "that kratom primarily inhibited intestinal CYP3A", an enzyme that breaks down certain drugs. They warn that "Co-consuming kratom with certain drugs extensively metabolized by CYP3A may precipitate serious interactions." That study used tea, not an extract.

Poison Control's online tool does not handle mixed exposures at all. It tells anyone "Exposed to more than one product or substance" to call instead.

What nobody can tell you about mitragynine toxicity

This page prints no safe amount. Mayo Clinic notes that many problems linked to pain medicines happen at high doses or with long use, then says: "Experts don't know what level of kratom can cause those problems."

That reaches our own shelves. Our King K product pages carry serving suggestions, and nothing in the sources on this page supports a serving size for any product, ours included.

Regulators say the same about lines on paper. In its notice of October 14, 2026, which proposes a threshold for the concentrated minor alkaloid and MGPI, DEA wrote that "neither HHS nor DEA has made a finding that these substances are safe to use at below-threshold levels." A legal line in a proposal is not a safety line.

Blood numbers do not settle it either. The 2022 review describes a Nevada study of death certificates in which blood mitragynine did not differ significantly between deaths where it was listed as causing or contributing and deaths where it was only identified.

FDA says "there is much that is not known scientifically about kratom." NIDA adds the everyday problem: "Importantly, kratom products vary, so effects are difficult to predict." And in its 2024 alert, FDA noted that "consumers may believe kratom products are safe because kratom is a plant material". Being a plant is not a safety finding.

What to do, and what clinicians do

Your part is the phone call. Poison Control's guidance is blunt: "If the individual collapses, has a seizure, has trouble breathing, or can't be awakened: Call 911 IMMEDIATELY." Short of that, "call a poison center at 1-800-222-1222 to speak with a poison expert right away." The federal Poison Help line says the number "connects you to your local poison center", in over 100 languages.

Have the product with you, and say what else was taken. StatPearls notes that "Kratom is not detected on routine drug screens" and that evaluation relies mainly on symptoms and the patient's history. Our page on what can cause a false positive for kratom covers testing from the other side.

StatPearls also describes what clinicians do: monitoring of breathing and the airway, consultation with a local poison control center or a bedside toxicologist, and standard anti-epileptic treatment for seizures. On naloxone, the opioid reversal drug, it is careful: "Although reversal agents, such as naloxone, are available for opioid overdose, the efficacy of reversal agents in kratom toxicity has not been well established." It goes on: "However, naloxone should be administered when the clinical presentation is consistent with an opioid toxidrome, and severe respiratory depression is present." Those are clinical decisions, one more reason to call rather than guess.

Then report it. FDA "encourages health care professionals and consumers to report any adverse reactions to the FDA's MedWatch program or the Safety Reporting Portal." If the product was one of ours, you can also tell us through our contact page; that never replaces the calls above.

Federal status on November 3, 2026

On November 3, 2026 the kratom leaf and mitragynine are not federally controlled, and MGPI, MGM-15 and MGM-16 have been in Schedule I since August 26, 2026. DEA's notice of October 14, 2026 proposing a threshold for the concentrated minor alkaloid and MGPI had produced no order as of November 3, 2026.

Not controlled does not mean lawfully marketed: FDA says "kratom is not lawfully marketed in the U.S. as a drug product, a dietary supplement, or a food additive in conventional food." The proposed line turns on what a product contains, not on whether it is leaf or extract, so selling extracts settles nothing about which side of it a product falls on. That is for testing and counsel, not legal advice from us.

Mitragynine toxicity questions

What is mitragynine toxicity?

Harm from too much kratom, or from kratom taken with other substances, as clinicians describe it. StatPearls lists signs from agitation and a fast heart rate to seizures and liver injury, and says definitive management practices still need further research.

What are the signs clinicians report?

NIDA's list from case reports includes confusion, tremors and seizures, high blood pressure and slow breathing, nausea and vomiting, and liver problems. Anyone who collapses, has a seizure, has trouble breathing or cannot be woken needs 911.

Is kratom toxicity the same as withdrawal?

No. Toxicity is harm from too much or from a bad combination; withdrawal follows when regular use stops. New York's health department says "Long-term, frequent use can lead to tolerance, dependence, and withdrawal symptoms similar to those experienced with opioids." Withdrawal belongs with a clinician, and kratom is not a treatment for it.

Are concentrated kratom extracts riskier?

New York's health department says "Kratom's toxicity may be worsened when an element of the kratom leaf is concentrated and consumed". The 2026 poison center analysis could not separate leaf from concentrated products. We sell concentrated extracts, and we do not claim ours are safer.

Who should I call about a kratom reaction?

Call 911 if someone collapses, has a seizure, has trouble breathing or cannot be woken. Otherwise call Poison Control at 1-800-222-1222, which is free, confidential and open around the clock. Say what was taken and what was taken with it. Clinical questions go to a clinician, not to us.

Disclaimer: this page summarizes publicly available material as of November 3, 2026 and links to primary sources. Case reports and case series describe individual patients, poison center figures count reports rather than people harmed, and animal and test-tube findings are not human effects. It is general information, not legal or medical advice. Statements about botanical products have not been evaluated by the Food and Drug Administration, and no product is intended to diagnose, treat, cure or prevent any disease.