This is the hardest of the kratom posts to write honestly, because the evidence points in two directions at once and almost everybody writing about kratom picks one direction and stops.
One side says kratom kills people. The other side says every reported death involved other drugs. Both of those statements are supported by the same dataset. This post works through what that dataset actually shows, what it cannot show, and which risks are well enough established to act on.
No dosing guidance appears here, and nothing in it should be read as encouragement to use kratom. Kratom’s legal status differs across Southeast Asia. Thailand regulates it under the Kratom Act B.E. 2565, but it remains controlled in Malaysia under the Poisons Act 1952 and banned in Myanmar under the Narcotic Drugs and Psychotropic Substances Law. See the kratom law post for details. This article does not encourage use anywhere kratom is banned.
What the case-report literature actually contains
The most careful analysis available is a 2025 review in Frontiers in Pharmacology that evaluated every published case report attributing an acute adverse effect to kratom. The numbers are worth stating precisely:
- 95 cases drawn from 59 published papers
- 55 cases had mitragynine confirmed toxicologically — 35 fatal, 20 survivors
- 40 cases had no toxicological confirmation at all, despite the authors attributing the effects to kratom
That last line matters. Nearly half the published “kratom cases” rest on a history taken from a patient or a family member, with no analytical confirmation that kratom was involved.
In the fatal cases, 32 of 35 (91%) involved other substances. In the survivors, only 7 of 20 (35%) did. The difference is statistically robust (p = 0.0002). The most common co-substances in the fatal group were benzodiazepines, SSRIs and opioids.
Of the 35 deaths, six were attributed to mitragynine toxicity alone and fifteen to mixed drug intoxication. The other 14 were classified in a scattered way:
- 3 as natural death (cause unknown)
- 2 as possible kratom or drug toxicity, not definitive
- 2 as drug toxicity with kratom as a possible contributor
- 2 as drug toxicity with kratom not contributory
- 1 as kratom intoxication with possible drug–drug interactions
- 4 as other specific causes: aspiration, cardiac arrest, asthma attack and severe coronary atherosclerosis
Pulmonary findings (oedema, congestion, pleural effusion) appeared in 74.3% of fatalities.
Among survivors, the dominant presentation was seizure: 12 of 20 cases in the review’s tables (its text gives 11). Six seizure cases had no toxicological evidence of other substances. However, most of the seizure data come from a single series that did not list the compounds it tested for. The testing also did not cover antihistamines, although two patients with negative screens reported taking kratom with diphenhydramine.
The authors’ conclusion, quoted as they wrote it: “the literature provides insufficient evidence to support the claim that kratom consumption alone increases the risk of severe acute adverse health effects,” and “most adverse effects coincided with polypharmacy, not kratom alone.”
How to read that. It is not a clean bill of health. It is a statement that the published case series cannot separate kratom’s contribution from that of the other drugs present, in most of the cases where someone died. That is a limitation of the evidence, not a finding of safety. Six deaths attributed to mitragynine alone is not zero. And the seizures in surviving patients, some with no other substance detected, are a signal that deserves more study, given the screening gaps above.
Liver injury: the risk with the best evidence
This is where the case for real, kratom-attributable harm is strongest, and it is chronically underdiscussed.
The NIH LiverTox database assigns kratom a likelihood score of B, meaning a likely cause of clinically apparent liver injury. That is a substantive classification, not a theoretical concern.
The clinical picture:
- Pattern: typically cholestatic or mixed, and it can be severe — serum bilirubin rising above 20 mg/dL is documented
- Latency: onset generally 1 to 8 weeks after starting regular use of powder or tablets. A case series from the US Drug-Induced Liver Injury Network reported a median of about 22 days (range 15–49).
- Dose: no threshold established. Reported cases range from single weekly doses to 60 tablets in a week
- Outcome: patients “usually recover once it is discontinued.” Cholestasis can be prolonged. Corticosteroids and N-acetylcysteine have been tried without proven benefit
The practical implication: jaundice, dark urine, pale stools or unexplained itching in a regular kratom user is not a coincidence to wait out. It is a reason to stop and see a doctor, and to tell that doctor about the kratom. Patients often leave it out because they think of it as a herb rather than a drug.
Dependence and withdrawal
This one is not seriously disputed any more.
Both the Current Addiction Reports review of 7-OH and the StatPearls clinical review document opioid-like withdrawal, tolerance, and kratom use disorder, with case reports of hospitalisation. The withdrawal syndrome resembles opioid withdrawal, which is unsurprising given the receptor pharmacology described in the kratom chemistry post.
There is a treatment implication worth knowing. Multiple case series support buprenorphine-based treatment for kratom withdrawal. By extrapolation it may also help with 7-OH use disorder, including extended-release formulations. If someone is trying to stop and finding they cannot, this is a treatable condition with an established approach. It is not a moral failure and not something to manage alone.
Drug interactions — the specific ones
Kratom’s interaction profile is not generic hand-waving. Several mechanisms are documented, and each has concrete consequences.
CYP2D6 and CYP3A4 inhibition. This is the most widely documented mechanism. In laboratory studies, mitragynine inhibits CYP2D6 and CYP3A, including CYP3A4. These enzymes clear a large share of prescription drugs. A 2023 review in Drug Metabolism and Disposition concludes that kratom can cause pharmacokinetic interactions through these enzymes, so drugs taken with it can reach higher levels than expected. Modelling predicts a higher risk for CYP3A substrates than for CYP2D6 substrates, and clinical interaction studies are still limited.
UGT inhibition. Mitragynine inhibits UDP-glucuronosyltransferase enzymes. Drugs cleared by UGT can therefore accumulate to supratherapeutic levels. The clinical literature names buprenorphine and ketamine as examples. That is an awkward fact, because buprenorphine is also the treatment for kratom withdrawal. It is a reason for a clinician who knows about the kratom use to handle the prescribing, not a reason to avoid treatment.
CNS depressant stacking. The fatal-case pattern is not subtle. Benzodiazepines, opioids and SSRIs are the three classes that recur. Whatever the independent risk of kratom is, the risk of kratom combined with any of these is demonstrably higher.
Alcohol and mixed drinks. Alcohol adds another depressant to the mix. In southern Thailand, recent mixed-drink preparations (‘4x100’) that combine kratom with other substances have been associated with harm.
The risk that changed: concentrated 7-OH products
Everything above concerns leaf and leaf preparations. A different product entered the market recently and it is not the same thing.
As explained in the kratom chemistry post, fresh leaf contains little or no 7-hydroxymitragynine (7-OH). Products enriched with isolated 7-OH deliver it at concentrations the plant itself does not produce.
The forensic and regulatory picture:
- The Center for Forensic Science Research and Education reported that in late 2024, 7-OH “emerged as the primary component in drug products being marketed and sold as ‘Kratom’ or ‘7OHM’”
- A study cited in the 2026 Current Addiction Reports review found elevated 7-OH levels in products misbranded as kratom
- In 2025 the FDA issued warning letters to seven companies marketing concentrated 7-OH products. HHS/FDA formally recommended Schedule I classification on 29 July 2025.
- US status as of October 2026: the DEA has not yet issued a temporary scheduling order for 7-OH itself. A July 2026 notice of intent was not followed by an order. On 9 October 2026 the US Department of Justice announced that the DEA will issue a new notice using HHS’s updated concentration and ratio thresholds. Three related compounds were temporarily placed in Schedule I on 26 August 2026: mitragynine pseudoindoxyl, MGM-15 and MGM-16.
- 7-OH has been described as a partial mu-opioid agonist “potentially comparable to other full opioid agonists”
And a detail that matters clinically: standard immunoassay drug screens do not reliably detect 7-OH. A patient presenting with opioid-toxidrome features may screen negative on a routine panel. If you are ever in an emergency department in this situation, say the word “kratom” out loud — the test will not say it for you.
Who should not use kratom
Drawing from the clinical reviews and from Thai statutory restriction:
Statutory bar in Thailand — the Kratom Act B.E. 2565 prohibits sale to:
- Anyone under 18
- Pregnant women
- Breastfeeding women
Thai rules for kratom-containing food products, including labelling, are covered in the kratom law post.
Clinically contraindicated or high-risk:
- Existing liver disease — the hepatotoxicity signal is the best-established harm
- Cardiac, renal, pulmonary or neurological disease
- Anyone taking benzodiazepines, opioids, SSRIs, or drugs cleared by CYP2D6, CYP3A4 or UGT
- Anyone with a history of polysubstance use
- Pregnancy — neonatal abstinence syndrome in newborns is documented, which is a considerably more concrete finding than most of what is discussed in this field
What is still unknown
Being straight about the gaps:
- Only a small number of controlled human studies exist, mostly on pharmacokinetics and experimental pain, and none establishes therapeutic efficacy. One example is a 2020 Malaysian double-blind, placebo-controlled cold-pressor study.
- Almost all other human data is observational, retrospective, or case-report based
- Dose–response relationships in humans are not established
- Cross-sectional studies of long-term users exist in Thailand and Malaysia, but there are no prospective long-term cohort studies
- The relative contribution of the minor alkaloids is unknown
The long-term gap is worth dwelling on. Thailand has a multigenerational population of kratom users, a legal framework that makes research possible, and universities capable of running the studies. Prospective cohort studies here would be some of the most valuable kratom research anywhere.
The honest summary
Kratom leaf is not the lethal substance its harshest critics describe, and the case-report literature genuinely does not support that claim. Nor is it the harmless herb its vendors describe. It causes liver injury with a likely causality rating. It produces dependence and an opioid-like withdrawal syndrome. It has real, specific drug interactions through CYP2D6, CYP3A4 and UGT. And the seizure reports in surviving patients are a signal that deserves more study.
The concentrated 7-OH products now circulating are a different and more dangerous proposition than the leaf, and conflating them is the single biggest source of confusion in the public conversation — in both directions.
If you are using kratom and finding you cannot stop, that is a recognised clinical condition with an established treatment. Talk to a doctor, and tell them what you have been taking.
Sources:
- “The acute adverse health effects of kratom: an evaluation of case reports”, Frontiers in Pharmacology, 2025
- “Kratom”, LiverTox: Clinical and Research Information on Drug-Induced Liver Injury, NIH
- US Drug-Induced Liver Injury Network kratom case series (Navarro et al.), The Liver Meeting, 2019
- “Kratom”, StatPearls, NCBI Bookshelf
- Tanna et al., “Translating Kratom-Drug Interactions: From Bedside to Bench and Back”, Drug Metabolism and Disposition, 2023
- Vicknasingam et al., “Kratom and Pain Tolerance: A Randomized, Placebo-Controlled, Double-Blind Study”, Yale Journal of Biology and Medicine, 2020
- “7-Hydroxymitragynine (7-OH): Clinical Implications of a Potent, Unregulated Opioid Partial Agonist Derived from Kratom”, Current Addiction Reports, 2026
- “7-Hydroxy Mitragynine New Drug Monograph”, NPS Discovery / CFSRE, 2025
- US Department of Justice, “Department of Justice Announces Updates to Emergency Scheduling Actions for 7-OH and Related Opioid…”, 9 October 2026
- Kratom Act B.E. 2565 (Thailand)