Kratom

Mitragyna speciosa

Ketum, Biak, Biak-Biak, Thang, Kakuam

Psychoactive Class

Opioid Stimulant (low doses)Depressant (high doses)

Chemical Class

Kratom is a tropical plant (Mitragyna speciosa) native to Thailand and Southeast Asia, where its leaves have been used as a traditional medicine for centuries.¹ Botanically related to coffee, it contains the indole alkaloids mitragynine and 7-hydroxymitragynine.¹ Kratom produces dose-dependent effects, acting as a stimulant at lower doses and producing opioid-like depressant effects at higher doses.¹ It is considered habit-forming.² Multiple strains exist, typically distinguished by vein color and region of origin.³

Dosage & Duration

Dosage

Threshold~0.5 g

Light0.5-1.5 g

Moderate1.5-3 g

Strong3-6 g

Heavy6+ g

These ranges apply to plain leaf material only. Alkaloid content can vary substantially between different batches and botanical sources, making precise dosing difficult. Individual sensitivity also varies widely, with some users experiencing paradoxically stronger effects at lower doses. Given this variability between batches and individual responses, these figures should be treated as approximate guidelines rather than exact recommendations.

Duration

Onset10-40 minutes

After Effects1-12 hours

Total2-5 hours

Subjective Effects

Effects vary widely by individual, dose, and context.

Physical

The physical effects of kratom can be broken down into several components which progressively intensify proportional to dosage.

Pain relief Itchiness Constipation Difficulty urinating Pupil constriction Salivation Cough suppression

Cognitive

The cognitive effects of kratom can be broken down into several components which progressively intensify proportional to dosage.

Motivation enhancement Thought acceleration Anxiety suppression

Visual

Visual acuity suppression Double vision

Forked from Subjective Effect Documentation

by Josie KinsSeptember 2015.

Reagent Testing

Loading reagent data

Expected colorimetric results are being prepared.

Pharmacology

Pharmacodynamics

Kratom's pharmacological activity is primarily driven by two indole alkaloids, mitragynine and 7-hydroxymitragynine, both of which act as partial agonists at μ-opioid receptors⁴, with 7-hydroxymitragynine showing the higher affinity⁴⁵. While most data indicates agonist activity across all three classical opioid receptor subtypes, some findings suggest antagonism at the δ-opioid receptor and only low affinity for the κ-opioid receptor⁴¹. Both compounds display functional selectivity, notably lacking β-arrestin pathway recruitment⁴⁵. Mitragynine additionally stimulates α2-adrenergic receptors (reducing norepinephrine release), interacts with several serotonin, dopamine, and adenosine receptor subtypes, inhibits COX-2, and blocks voltage-gated calcium channels⁴. Kratom contains at least 54 alkaloids in total⁶, including rhynchophylline (a non-competitive NMDA receptor antagonist)⁷, which may contribute synergistically to the plant's overall pharmacological profile.

Pharmacokinetics

Both mitragynine and 7-hydroxymitragynine readily cross the blood-brain barrier⁸. Mitragynine undergoes hepatic metabolism via both phase I and phase II pathways, with resulting metabolites excreted in urine⁸¹. In vitro studies indicate that kratom extracts inhibit CYP3A4, CYP2D6, and CYP1A2, suggesting significant potential for drug interactions⁹¹⁰.

Metabolitesnone documented yet

Interactions

Dangerous

Highest risk

These combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.

AlcoholBenzodiazepinesCocaineDXMGHB/GBLKetamineMXEPregabalinTramadol

Unsafe

Avoid

There is considerable risk of physical harm when taking these combinations, they should be avoided where possible.

Diphenhydramine

Caution

Use caution

These combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.

AmphetaminesMAOIsMephedroneNitrous oxidePCP

TripSit

Tolerance

Cross Tolerance

Opioids

Harm Potential

Addiction & Dependence

Psychological

Moderate

Kratom has a known addiction liability with approximately 25.5% of regular users meeting criteria for substance use disorder.¹¹ Dependence may develop relatively quickly in vulnerable individuals, with tolerance often noted within weeks to months.⁵ Relapse risk is high, reported at 78-89% at three months post-cessation.

Physical

Moderate

Physical dependence develops with regular use, producing withdrawal symptoms including irritability, diarrhea, muscle and bone pain, insomnia, decreased appetite, restlessness, fever, and low motivation.¹² While often reported as less severe than traditional opioid withdrawal,¹³ kratom withdrawal can still be significant, and severe cases may warrant treatment approaches similar to opioid addiction.¹⁴

Toxicity

Hepatic

Kratom use is associated with acute liver injury in some users, presenting with abdominal discomfort, dark urine, pruritus, and jaundice;¹⁵ however, many users do not develop liver injury, and risk factors remain unclear.

Musculoskeletal

Rhabdomyolysis has been reported as a rare but serious complication, primarily associated with high-dose use.¹⁷

Cardiovascular

Elevated heart rate and blood pressure may occur during use; tachycardia was reported in approximately 17% of poison control exposures,¹⁸ though serious cardiac events are uncommon.

Psychosis Risk

Psychosis and hallucinations have been reported with frequent high-dose use, with hallucinations noted in approximately 4.8% of poison control cases.¹⁸ Kratom use has a small but statistically significant association with externalizing mental health disorders and may worsen existing conditions.¹⁹ It remains unclear whether kratom directly causes psychosis or unmasks pre-existing vulnerability.

Seizure Risk

Seizures were reported in approximately 6.1% of poison control center exposures.¹⁸ Risk appears primarily associated with frequent use of high doses or overdose situations. At typical recreational doses, seizure risk appears low.

History & Culture

Traditional Use in Southeast Asia

Kratom is indigenous to Cambodia, Thailand, Indonesia, Malaysia, Myanmar, and Papua New Guinea, where its leaves have been used in traditional herbal medicine since at least the nineteenth century.²⁰ The plant has historically been consumed through chewing, smoking, and…

Legality

International

Kratom, mitragynine, and 7-hydroxymitragynine do not appear in the schedules to the 1961 Single Convention, the 1971 Convention on Psychotropic Substances, or the 1988 Convention against Illicit Traffic. The WHO Expert Committee has reviewed kratom and recommended continued surveillance rather than international scheduling.

By Country

United StatesNot scheduledNot federally scheduled

Controlled Substances Act, 21 U.S.C. § 811(h), and 21 C.F.R. Part 1308; DEA notices of intent, 91 Fed. Reg. 40917 (July 6, 2026) (DEA-1570) and 91 Fed. Reg. 40909 (July 6, 2026) (DEA-1644)^48495051

As of July 15, 2026, kratom (Mitragyna speciosa), mitragynine, and 7-hydroxymitragynine are not federally scheduled under the Controlled Substances Act. DEA published notices of intent—not effective temporary scheduling orders—covering 7-hydroxymitragynine only above specified concentration or per-article thresholds and, separately, mitragynine pseudoindoxyl, MGM-15, and MGM-16; both notices state that an order will be published no earlier than August 5, 2026 and will take effect upon publication. The announced actions do not schedule the kratom plant or mitragynine as such, and botanical kratom at or below the stated 7-hydroxymitragynine threshold is outside the announced 7-hydroxymitragynine action.

By state

Alabama

Illegalschedule_i

Arizona

Restrictedkratom_consumer_protection_act

California

Not scheduledCal. Health & Safety Code §§ 11054-11058…

Guam

Not scheduledNo territorial control identified

Illinois

Restrictedminor_possession_and_sale_restriction

Indiana

Illegalschedule_i_synthetic_drug

Iowa

Not scheduledNo state scheduling

Maine

Not scheduledNo state scheduling

Massachusetts

Not scheduledNo state scheduling

Missouri

Not scheduledNo state scheduling

Nebraska

Legal (regulated)Kratom Consumer Protection Act

Nevada

Legal (regulated)Kratom product restriction

Oklahoma

Legal (regulated)Kratom Consumer Protection Act

Oregon

Legal (regulated)Oregon Kratom Consumer Protection Act

Rhode Island

Legal (regulated)Rhode Island Kratom Act

South Dakota

Legal (regulated)Kratom product requirements

Texas

RestrictedKratom product regulation

Utah

RestrictedKratom Consumer Protection Act

Virginia

RestrictedConsumer-protection restriction

Washington

Not scheduledNo state control identified

West Virginia

RestrictedPlant-based product regulation

Wisconsin

IllegalSchedule I

ColombiaNot scheduledNot listed

Resolution 315 of 2020²⁴

Kratom (Mitragyna speciosa) and its principal alkaloid mitragynine are not listed in Annex 1 of Colombia's Resolution 315 of 2020, the national list of specially controlled and monitored substances. The resolution extends control to mixtures and products containing substances listed in Annex 1 and to specified salts, isomers, hydrates, and related variations of those listed substances. It does not establish a class-wide analogue provision that captures kratom or mitragynine.

New ZealandIllegalClass C

Misuse of Drugs Act 1975²⁶

New Zealand controls mitragynine as a Class C controlled drug under the Misuse of Drugs Act. Unauthorized possession, supply, importation, and manufacture of controlled drugs are offences under the Act.

PolandIllegalI-N

Regulation of the Minister of Health of 17 August 2018 on the list of psychotropic substances, narcotic drugs and new psychoactive substances (Dz.U. 2018 poz. 1591)²⁸²⁹

Since 21 August 2018, kratom (Mitragyna speciosa) has been listed as a Group I-N narcotic drug in the Regulation of the Minister of Health, including live plants, dried material, seeds and extracts. The same group separately lists mitragynine, kratom's principal alkaloid. Group I-N narcotic drugs may be used only for medical, industrial or research purposes; unauthorized possession is subject to forfeiture, and unlawful manufacture and trade are criminal offences.

SingaporeIllegalFirst Schedule

Misuse of Drugs Act 1973³²

Singapore lists mitragynine in the First Schedule to the Misuse of Drugs Act. The Act's controlled-drug provisions apply to listed substances and criminalize unauthorized possession, trafficking, import, export, and manufacture.

SwedenIllegalBilaga 1

Förordning (1992:1554) om kontroll av narkotika, as amended by SFS 2025:77^35363738

Kratom (Mitragyna speciosa) has been classified as a narcotic in Sweden since 11 March 2025 under Annex 1 to the Ordinance (1992:1554) on control of narcotics. Unauthorised possession, use, manufacture, sale, and other handling of kratom are narcotics offences under the Narcotics Criminal Act (1968:64).

United Arab EmiratesIllegalSchedule No. (4)

Federal Decree-Law No. (30) of 2021 on Combating Narcotic Drugs and Psychotropic Substances⁴²⁴³

Kratom (Mitragyna speciosa) is listed in Schedule No. (4) to Federal Decree-Law No. (30) of 2021 on Combating Narcotic Drugs and Psychotropic Substances, which took effect on 2 January 2022. The decree-law treats the substances in Schedules (1) through (4) as narcotic drugs; unauthorized possession, production, import, export, sale, and use are criminally prohibited.

AustraliaIllegalSchedule 9

Poisons Standard²³

Australia lists mitragynine in Schedule 9 of the Poisons Standard. Schedule 9 substances are prohibited substances whose manufacture, possession, sale, or use is prohibited except for approved medical or scientific research.

IrelandIllegalSchedule 1

Misuse of Drugs Regulations 2017²⁵

Ireland places mitragynine and 7-hydroxymitragynine in Schedule 1 of the Misuse of Drugs Regulations. The Schedule 1 classification subjects the substances to the controls of the Misuse of Drugs framework.

NorwayIllegalNarkotikalisten

Forskrift om narkotika (FOR-2013-02-14-199)²⁷

Kratom products containing mitragynine are controlled as narcotics under the Norwegian Narcotics Regulation, whose Narkotikalisten expressly lists mitragynine and 7-hydroxymitragynine. The regulation treats listed substances as narcotics; their possession, production, importation, and supply are subject to Norway's narcotic-drug controls.

RussiaIllegalList I

Government Resolution of the Russian Federation No. 681 of 30 June 1998, On Approval of the List of Narcotic Drugs, Psychotropic Substances and Their Precursors Subject to Control in the Russian Federation³⁰³¹

Kratom is prohibited in Russia because its principal alkaloid, mitragynine, is listed in List I of Government Resolution No. 681 of 30 June 1998. List I covers narcotic drugs whose circulation in the Russian Federation is prohibited; the listing therefore prohibits the circulation of mitragynine-containing kratom products.

South KoreaIllegal별표 1

Narcotics Control Act Enforcement Decree (마약류 관리에 관한 법률 시행령)³³³⁴

Mitragynine, the principal psychoactive alkaloid in kratom, is listed as a narcotic in Appendix 1 to the Narcotics Control Act Enforcement Decree. The Narcotics Control Act prohibits unauthorized handling of narcotics, including importation, possession, manufacture, and sale; kratom preparations containing mitragynine are therefore controlled as narcotics.

UkraineRestrictedСписок № 1

Cabinet of Ministers Resolution No. 770 of 6 May 2000, as amended by Resolution No. 1306 of 15 November 2024³⁹⁴⁰⁴¹

Kratom leaf (Mitragyna speciosa), mitragynine, and 7-hydroxymitragynine are listed in List No. 1 of Table II of Ukraine's controlled-substances schedule. Their circulation is restricted and subject to control measures under Ukrainian law. The amendment adding these entries took effect on 19 November 2024.

United KingdomRestrictedPsychoactive substance

Psychoactive Substances Act 2016^44454647

Kratom is subject to the Psychoactive Substances Act 2016 where it is supplied, produced, imported, or exported for psychoactive consumption. The Act defines a psychoactive substance as one capable of producing a psychoactive effect that is not exempted, and its current Schedule 1 does not exempt kratom. The relevant provisions came fully into force on 26 May 2016; the offences require the statutory knowledge, suspicion, recklessness, or intended-consumption conditions.

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Kratom

Contents

Dosage & Duration

Dosage

Duration

Subjective Effects

Physical

Cognitive

Visual

Reagent Testing

Pharmacology

Pharmacodynamics

Pharmacokinetics

Interactions

Dangerous

Unsafe

Caution

Tolerance

Harm Potential

Addiction & Dependence

Psychological

Physical

Toxicity

Psychosis Risk

Seizure Risk

History & Culture

Traditional Use in Southeast Asia

Legality

International

By Country

References

Source Pages

Citations

Further Reading

Suggest an edit

Kratom

Contents

Dosage & Duration

Dosage

Duration

Subjective Effects

Physical

Cognitive

Visual

Reagent Testing

Pharmacology

Pharmacodynamics

Pharmacokinetics

Interactions

Dangerous

Unsafe

Caution

Tolerance

Harm Potential

Addiction & Dependence

Psychological

Physical

Toxicity

Psychosis Risk

Seizure Risk

History & Culture

Traditional Use in Southeast Asia

Legality

International

By Country

References

Source Pages

Citations

Further Reading

Suggest an edit