| Accepted name | Mitragyna speciosa Korth. Pieter Willem Korthals published the name and its plate in the botanical volume of the Dutch natural-history survey of the East Indies; Plants of the World Online dates valid publication to 1841 (Korthals, 1841; POWO, 2026). |
| Principal synonyms | Stephegyne speciosa (Korth.) Korth.; Nauclea speciosa (Korth.) Miq.; Nauclea luzoniensis Blanco. The authority Mitragyna speciosa (Korth.) Havil. remains widespread in pharmacological literature, but the current Kew record accepts Korthals’s original combination as M. speciosa Korth. (POWO, 2026). |
| Family | Rubiaceae, the coffee and madder family; subfamily Cinchonoideae; tribe Naucleeae. |
| Order | Gentianales. |
| Geographic range | Native from southern Indochina to New Guinea: Cambodia, Myanmar, Thailand, Vietnam, the Malay Peninsula, Sumatra, Borneo, the Philippines and New Guinea. It is most characteristic of humid lowlands, river margins, swamp forest, seasonally flooded ground and secondary wet forest, and is widely planted in home gardens and commercial plots (Puff et al., 2021; POWO, 2026). |
| Local names | Thai krathom/kratom (กระท่อม), southern Thai thom, and regional ithang, kakuam; Malay ketum and biak; Indonesian and West Kalimantan purik, ketum and kratom; Philippine mambog. Spellings vary with transliteration, and several vernacular names extend to preparations rather than denoting the tree alone (Suwanlert, 1975; Singh et al., 2017). |
| Growth form | Evergreen or seasonally deciduous canopy tree, commonly 4–25 m high, sometimes taller, with a straight bole that may approach 1 m in diameter. Coppicing and repeated leaf harvest produce lower, many-branched cultivated forms. |
| Conservation | No current global IUCN assessment for the species was located. Its broad native distribution and extensive cultivation argue against immediate species-wide scarcity, but lowland wet-forest conversion, replacement of wild stands by narrow commercial stock and loss of locally selected lineages can reduce habitat and genetic diversity. Conservation status and biocultural continuity are therefore separate questions (POWO, 2026). |
The trunk has grey to grey-brown bark, smooth when young and shallowly fissured with age. Leaves are opposite and decussate, simple, glossy, broadly elliptic to ovate, usually about 8–20 cm long, with an acute or shortly acuminate tip. Twelve to seventeen pairs of prominent lateral veins arch toward the margin. Interpetiolar stipules—paired appendages between the leaf stalks—identify the Rubiaceae architecture. Leaves may become reddish before falling during dry or cool periods.
Numerous small, tubular, yellow to cream flowers are packed into globose terminal or axillary heads. The genus name refers to the mitre-like form of the stigma. Each fertilised flower develops into a small capsule; persistent calyces produce a bristling brown spherical fruiting head containing many minute, flattened, winged seeds. Sexual reproduction is accompanied by ready vegetative propagation from cuttings, a major route for household and commercial selection (Puff et al., 2021).
M. speciosa is one member of an Asian–African genus whose delimitation has changed as several African species were transferred to Hallea or Fleroya. Ethnopharmacological statements about “Mitragyna” cannot automatically be assigned to kratom.
Geography, season, leaf age, environment and genotype alter alkaloid ratios. Voucher-backed sampling in Thailand finds substantial regional and seasonal variation; a market label is not a chemical assay (Flores-Bocanegra et al., 2020; Sukrong et al., 2023).
Vein colour and commercial colour names are not formal botanical varieties. They can reflect leaf maturity, drying, fermentation, blending and branding, and have not been shown to predict effects reliably across vendors.
The expansion of clonal and seed-grown plantations creates large biomass without necessarily conserving the genetic range of riverine and swamp-forest populations. Population-genomic coverage across the native range remains limited.
Kratom leaves contain a complex suite of monoterpenoid indole alkaloids. More than forty alkaloidal constituents have been reported, but abundance varies markedly by accession and preparation. Mitragynine is usually the dominant alkaloid in Southeast Asian leaf; speciogynine, paynantheine and speciociliatine may each make substantial contributions, while 7-hydroxymitragynine is normally a minor or trace constituent and also forms metabolically from mitragynine. Oxindoles, flavonoids, triterpenoids and phenolics enlarge the chemical ensemble. A dried leaf, a standardised extract and a tablet enriched with 7-hydroxymitragynine cannot be treated as pharmacologically equivalent (Flores-Bocanegra et al., 2020; Chear et al., 2021; Avula et al., 2026).
Mitragynine and 7-hydroxymitragynine act at μ-opioid receptors, but their structures, efficacy and signalling differ from morphine. In recombinant systems mitragynine has relatively low-efficacy partial agonism at μ receptors and antagonist or very low-efficacy actions at δ and κ receptors; 7-hydroxymitragynine is much more potent. Hepatic CYP3A converts a fraction of mitragynine into 7-hydroxymitragynine, making metabolism part of mitragynine’s analgesic mechanism. Mitragynine pseudoindoxyl can arise through further metabolism or rearrangement and has mixed μ-agonist/δ-antagonist activity (Kruegel et al., 2016; Váradi et al., 2016; Kruegel et al., 2019).
The once-prominent claim that mitragynine’s apparent G-protein bias would by itself explain a safer opioid profile is now treated cautiously: measured bias depends on assay and reference ligand, while respiratory, rewarding and behavioural effects emerge from receptor efficacy, metabolites, exposure and the entire alkaloid matrix. Beyond opioid receptors, corynantheidine-related alkaloids bind α-adrenergic sites; paynantheine, speciogynine and mitragynine show distinct serotonin-receptor profiles, including 5-HT₁A agonist activity in preclinical work. Kratom is thus pharmacologically plural rather than a botanical delivery vehicle for one opioid (Obeng et al., 2020; León et al., 2021).
Encapsulated dried leaf and concentrated extracts show median mitragynine peak plasma times around one to under two hours, but elimination can be prolonged and accumulation occurs with repeated daily administration. Preparation, food, dose, metabolic genotype and co-medication change exposure (Huestis et al., 2024; 2026).
CYP3A is central to mitragynine clearance and 7-hydroxylation; CYP2D6 and other enzymes contribute to additional metabolites. Kratom alkaloids can also inhibit CYP2D6 and intestinal CYP3A, giving a mechanistic basis for some herb–drug interactions (Kamble et al., 2019; Tanna et al., 2023).
Analyses published in 2026 found commercial products with elevated 7-hydroxymitragynine inconsistent with ordinary leaf chemistry. Oxidation during processing and deliberate enrichment can move a product far beyond the Southeast Asian botanical baseline (Avula et al., 2026).
Whole-leaf effects cannot yet be allocated quantitatively among mitragynine, its stereoisomers, 7-hydroxymitragynine, oxindoles and non-alkaloidal constituents. Controlled comparisons of chemically complete, voucher-linked preparations remain scarce.
| Indigenous antiquity | Undated oral practice Thai and Malay sources describe leaf use as inherited village knowledge whose beginning could not be dated. This supports pre-colonial or early modern antiquity but does not establish a prehistoric chronology. No securely identified archaeobotanical kratom assemblage presently dates consumption (Suwanlert, 1975; Singh et al., 2017). |
| Botanical documentation | 1841 Korthals’s East Indies botanical work supplied the first valid scientific description and plate. European pharmacognosy subsequently isolated mitragynine in the 1920s; these events document colonial science, not the beginning of local use (Korthals, 1841; Field, 1921). |
| Ethnographic record | Twentieth century Surveys and clinical observations in Thailand described fresh-leaf chewing among market gardeners, peasants and labourers, folk treatment of diarrhoea and use in place of opium. Later Thai and Malaysian studies documented work endurance, pain modulation, sociability and management of opiate withdrawal (Suwanlert, 1975; Vicknasingam et al., 2010; Saingam et al., 2013). |
| Chronological limit | Open Assertions of “thousands of years” recur in commerce and advocacy but are not supported by a dated textual or archaeobotanical sequence. The appropriate historical formulation is long-standing and locally inherited, with secure written evidence from the nineteenth and twentieth centuries. |
| Fresh leaf | The most characteristic Thai practice is chewing a fresh leaf after removing the tough midrib, followed by water or another drink. Leaves may be taken intermittently across a working day. The sequence belongs to habitual bodily technique and social timing rather than a single bounded ceremony (Saingam et al., 2013). |
| Decoction | Fresh or dried leaves are simmered as a bitter tea in Thailand and Malaysia. Household and communal decoctions permit sharing and storage; sweetness or other flavourings may be added. Powder-filled capsules and concentrated shots are primarily modern commodity formats. |
| Ethnomedicine | Reported uses include fatigue, muscular and joint pain, diarrhoea, cough, fever, stomach complaints, diabetes, hypertension and opiate withdrawal. These are records of therapeutic practice and local efficacy claims; the clinical evidence differs by indication (Suwanlert, 1975; Vicknasingam et al., 2010). |
| Hospitality | Kratom may be offered with tea or coffee to guests, and asking a neighbour for leaves is described as ordinary reciprocity in southern Thai villages. Sharing ties the plant to household reputation and neighbourliness (Charoenratana et al., 2021). |
| 4×100 mixtures | From the late twentieth century, some southern Thai youth cultures combined kratom decoction, sweet caffeinated drinks and cough medicines or other ingredients. “4×100” became a policing and media category. Its mixed pharmacology and generational style distinguish it from fresh-leaf work practice (Singh et al., 2017). |
The ethnographic centre of kratom is not a specialist shamanic initiation comparable to ayahuasca, iboga or peyote traditions. Healing is usually domestic, lay and pragmatic: a plant known through bodily repetition, older users, neighbours and family transmission. Its authority lies in what it permits a person to do—work, travel, endure pain, withdraw from opium, receive a guest—more than in visions interpreted by an officiant. Where leaves enter small religious ceremonies or promises to a deity, they do so within broader Buddhist, Muslim and local spirit worlds rather than forming an autonomous “kratom religion” (Singh et al., 2017).
Gender is important. Thai and Malaysian studies have overwhelmingly recruited men, and female use has often been described as rare or stigmatised. This pattern reflects labour organisation, public sociability, drug law and research sampling as well as pharmacology. Women may cultivate, prepare, serve and trade leaves without appearing in user-centred surveys. The archive therefore records a masculine moral economy more clearly than the total gendered life of the plant.
“lively, relaxed, not stressed, energized, pumped, active and happy to work”Experiential item derived from southern Thai user research in Saingam et al. (2014, p. 280)
No securely documented, pan-Southeast Asian mythic cycle centred on M. speciosa has been published. This absence should neither be filled with an invented “kratom spirit” nor taken to mean that the plant is culturally inert. Thai accounts describe leaves promised or offered to deities and ancestors in some localities, and small religious observances occur within village life; the evidence is geographically particular and less extensive than the record for work, medicine and hospitality (Saingam et al., 2013; Singh et al., 2017).
The more richly evidenced cosmology is practical and moral. The body is understood through heat, chill, energy, pain, appetite, sleep and the ability to meet obligations. Kratom can index disciplined masculinity, industriousness and household provision when leaf use remains measured and socially integrated. The same plant can index dependency, youth disorder or criminality when attached to secret mixtures, theft, idleness or police categories. These are not timeless “beliefs” but contested classifications produced among users, families, village leaders, clinicians, monks, Muslim communities and the state (Saingam et al., 2013; Charoenratana et al., 2021).
A valued user is repeatedly described as capable of sustained labour without appearing drunk or disruptive. Energy, analgesia and composure become evidence of character because they maintain obligations to land, employer and household.
Offering leaves or tea places kratom beside coffee, tobacco and betel-like forms of everyday sociability. The home-yard tree becomes a small infrastructure of welcome, exchange and neighbourly access.
Some Thai accounts record leaves promised to a god when requesting help with lost objects or desired outcomes, and offered after success. Such practice indicates value and reciprocity; it does not establish a standardised kratom cult.
The category “narcotic” was imposed through Thai and Malaysian law, clinical addiction discourse and international drug-policy vocabularies. Community studies show that villagers may instead classify fresh leaf as food-like tonic, medicine or ordinary custom while treating mixed preparations differently.
| Household tree | A mature tree beside house, orchard, canal or rubber plot holds practical memory: named ownership, pruning history, preferred leaf, shade and a reliable source for neighbours. Prohibition made such trees targets of felling and concealment; decriminalisation returned them to visible domestic space. |
| Leaf bundle | Fresh glossy leaves, selected and folded or carried to work, preserve botanical recognisability and interpersonal provenance. Their perishability keeps circulation local. |
| Kettle and bottle | Decoction pots, cups, recycled bottles and shared serving vessels transform leaves into a mobile social drink. In prohibition contexts the same objects could become evidence of illicit preparation. |
| Powder and capsule | Drying and milling stabilise kratom for export but erase leaf form, locality and many sensory cues. Green powder enters supplement jars, capsules and online “strain” taxonomies generated by global marketing. |
| Extract and 7-OH tablet | Shots, gummies, pressed tablets and purified or semi-synthetic alkaloid products embody industrial concentration. Their packaging invokes wellness, energy or opioid substitution while their chemistry may bear little resemblance to fresh leaf. |
Korthals’s plate translated an Indigenous and Malay-world tree into a taxonomic specimen within the Dutch East Indies. In Thailand, the 1943 Kratom Act prohibited planting and required trees to be cut. Fiscal history matters: kratom use competed with revenue from the state opium monopoly, so criminalisation cannot be explained only as a response to pharmacological harm. Later narcotics law consolidated the plant as a controlled drug. Felling, police surveillance and the opposition between respectable leaf chewing and suspect youth mixtures became part of kratom’s material and symbolic life. The 2021–2022 Thai reforms reversed the legal category while retaining rules for sale, advertising and restricted purchasers.
Fresh-leaf chewing and tea can become perceptible within roughly 10–30 minutes; swallowed dried powder commonly begins within about 30–60 minutes. Human pharmacokinetic studies place median mitragynine plasma peaks around one to under two hours, though felt onset and plasma maximum are not identical.
Principal subjective effects are often described over approximately 3–6 hours, with residual analgesia, calm or sleepiness extending longer. Repeated leaf chewing across a workday produces a sustained plateau rather than a single session arc; mitragynine itself has a much longer terminal elimination phase.
Usually mild to moderate in traditional fresh-leaf use, sufficient to alter fatigue, pain and sociability while leaving coordinated labour possible. Extracts and 7-OH-enriched products can generate a more strongly opioid-like state and should not be used to infer the intensity of village leaf practice.
Alertness, physical stamina, willingness to begin or continue repetitive work, talkativeness, brightened mood, reduced hunger and a narrowing of attention toward the task. Users may describe being both energised and relaxed rather than conventionally stimulated.
Warmth, analgesia, bodily ease, miosis, emotional quiet, slowed movement, contentment, drowsiness and dreamlike reverie become more prominent with greater exposure or after exertion. Nausea, sweating, dizziness, itching or dysphoria may interrupt this field.
Low. Complex imagery, entity encounters and radical perceptual transformation are not normative features of documented traditional use. Hallucination and delirium appear chiefly in exceptional intoxication, mixed-drug cases or clinical reports, not as a sought ritual technology.
Kratom complicates the category “visionary plant” because its culturally salient alterations often concern capacity rather than spectacle. Fatigue recedes; painful joints and muscles move into the background; repetitive labour acquires momentum; conversation remains easy; appetite and worry can be deferred. The perceptual world may appear largely ordinary while the relationship between intention, effort and bodily resistance changes. This is a genuine psychoactive phenomenology, but its unit of analysis is the working body in a social day (Saingam et al., 2013; Singh et al., 2017).
The widely repeated “stimulant at low dose, sedative at high dose” formula is a useful first approximation, not a universal switch. Alkaloid profile, preparation, tolerance, food, metabolism, expectation and activity all matter. A labourer can experience calm and energy together; warmth and analgesia may facilitate work rather than sleep; repeated use may make withdrawal relief feel like stimulation. Qualitative accounts therefore describe overlapping activation and opioid-like comfort rather than two clean phases.
Daily users may increase leaf frequency or feel unable to work fully with less than usual. The social usefulness of kratom and physiological adaptation can reinforce one another (Saingam et al., 2014).
Reported features include craving, fatigue, irritability, restlessness, insomnia, muscular and joint pain, runny nose, diarrhoea and chills. Severity varies; dependence is well documented without implying that every regular user meets a disorder threshold (Singh et al., 2014).
Southern Thai users described a culturally salient cluster of chill, trembling, bone or joint pain and urgent avoidance of rain. It links withdrawal-like bodily sensitivity to monsoon work and local explanatory language (Saingam et al., 2013).
Several Malaysian studies found broadly comparable neuropsychological performance between regular users and controls, but observational designs cannot settle all effects of lifetime use, product variation or concentrated modern preparations.
“it helps them to overcome the burden of their hard work and meager existence”Suwanlert (1975, p. 21), summarising Thai labourers’ stated reason for leaf use within an early psychiatric study
Kratom is now planted on a scale that makes simple species scarcity an inadequate measure. In Thailand, legal home cultivation can sustain old household trees and local exchange. In West Kalimantan, plantation expansion creates income but can favour a narrow set of fast-growing stocks and alter riverine, peatland and mixed-agroforest ecologies. Wild populations across Cambodia, Myanmar, Vietnam, the Philippines and New Guinea remain less chemically and genetically studied than commercial Thai and Indonesian material. Conservation priorities include wet lowland habitat, population-level genetic diversity, locally preferred trees and the knowledge that distinguishes leaf use from an anonymous export powder.
| Thailand | Decriminalisation opened visible fresh-leaf stalls, bottled drinks, foods, cosmetics, community enterprises and licensed export. The legal market reframes a formerly illicit village plant as agricultural and herbal commodity while sale and advertising remain regulated. |
| Indonesia | West Kalimantan is a principal source of dried leaf powder for the United States and other markets. Smallholders depend on volatile export prices, intermediary mills and regulatory decisions. Minister of Trade Regulations 20 and 21 of 2024 restricted exports to specified processed forms, quality standards and licensed channels rather than prohibiting all trade; revisions continued in 2025 (Ministry of Trade of Indonesia, 2024). |
| Malaysia | A long-standing local ketum economy persists under Poisons Act control. Informal leaf and decoction circulation coexists with enforcement, public-health debate and proposals for regulated cultivation or pharmaceutical research. |
| United States | Online vendors, smoke shops, “tea bars”, capsules, powders, shots and tablets have produced the largest visible consumer market outside Southeast Asia. Industry advocacy has promoted state consumer-protection acts, age limits, testing and labelling while regulators contest kratom’s lawful status as food or supplement. |
| Commodity differentiation | Botanical leaf powder, mitragynine-rich extracts and enhanced 7-OH products now occupy different price, potency and regulatory strata. Calling all three “kratom” obscures the economic process by which oxidation, extraction and branding create new pharmacological commodities. |
| International | Kratom, mitragynine and 7-hydroxymitragynine are not scheduled under the UN drug conventions. The WHO Expert Committee on Drug Dependence conducted a pre-review in 2021 and did not recommend a critical review, citing insufficient evidence for international control while retaining surveillance (WHO, 2021; 2022). |
| Thailand | Kratom was removed from the Narcotics Code with effect from 24 August 2021. The Kratom Plant Act B.E. 2565 (2022) governs sale, import/export, advertising and restricted purchasers while permitting cultivation and possession (Kingdom of Thailand, 2022). |
| Malaysia | Mitragynine is listed as a psychotropic substance under the Poisons (Psychotropic Substances) Regulations 1989 and controlled through section 30 of the Poisons Act 1952. Unauthorised possession, use, processing, sale, supply, import and export of mitragynine-containing material are offences. |
| Indonesia | Kratom is not uniformly regulated as a narcotic. Export is governed through trade rules introduced in 2024 and amended in 2025: raw whole leaves and certain forms are restricted, while qualifying crumbs or powder meeting contamination, particle-size and licensing standards may be exported. |
| United States | Mitragynine and ordinary botanical kratom were not federally scheduled on this date; several states and localities prohibit them and others regulate age, testing or labels. FDA states that kratom is not lawfully marketed as a drug, dietary supplement or conventional-food additive. DEA published July 2026 notices of intent to place 7-OH above defined thresholds, mitragynine pseudoindoxyl, MGM-15 and MGM-16 temporarily in Schedule I; no final temporary order had appeared in the Federal Register by 7 August 2026 (FDA, 2025; DEA, 2026). |
| United Kingdom | Kratom is not named in the Misuse of Drugs Act schedules, but production, supply, possession with intent to supply and import/export for human psychoactive use fall within the Psychoactive Substances Act 2016. Simple possession is generally not an offence outside custodial institutions. |
| Australia and New Zealand | Australia places M. speciosa and mitragynine in Schedule 9 of the Poisons Standard. In New Zealand mitragynine-containing kratom is treated as a prescription medicine, while unapproved therapeutic supply and import are restricted. Jurisdiction and product form remain decisive. |
Patent claims increasingly isolate functions from the ethnobotanical whole: opioid-receptor-modulating mitragynine analogues, deuterated derivatives, pseudoindoxyls, purified compositions, extraction and delivery systems, and methods aimed at pain, mood or substance-use disorders. WO2017165738A1 claims mitragynine-related opioid modulators; WO2020160280A1 covers deuterated mitragynine analogues; WO2024171204A1 concerns mitragynine purification; and US20230364172A1 addresses oral and buccal delivery. These patents do not confer ownership of M. speciosa or Southeast Asian traditional knowledge, but they can control particular molecules, processes, formulations and therapeutic uses. The legal distinction is clear while the benefit-sharing question remains open.
| Nicotiana rustica | Species monograph: another labour-linked, socially shared plant stimulant whose ritual and toxicological histories differ sharply from kratom. ETHNOBOTANICAL COMPARATOR |
| Erythroxylum coca | Species monograph: Andean leaf-chewing traditions organised around work, reciprocity and endurance; a useful comparison in colonial prohibition and commodity transformation. LABOUR-PHENOMENOLOGY COMPARATOR |
| Tabernanthe iboga | Species monograph: an African indole-alkaloid plant with initiatory and visionary institutions absent from the documented kratom complex. INDOLE-ALKALOID CONTRAST |
| Peganum harmala | Species monograph: an Old World household medicine, protective fumigant and harmala-alkaloid source. Shared “traditional medicine” labels conceal distinct chemistry and social practice. HOUSEHOLD-MEDICINE COMPARATOR |
| Clinical Psychedelic Ritual Complex | Contemporary clinical infrastructure for psychedelic-assisted therapy. Kratom’s emerging trials concern botanical pharmacology, pain and dependence rather than a therapist-guided visionary ritual. CLINICAL CONTRAST |
| Mitragyna parvifolia | South Asian congener used in regional medicine and timber economies; pharmacological statements about the genus require species-level vouchers. BOTANICAL CONGENER |