Definition
Kratom is the commercial and colloquial name for the leaves of the tree Mitragyna speciosa Korthals, or for the dry powder obtained by grinding them. Botanically it is an evergreen tree of the madder family (Rubiaceae) - the same family that includes coffee (Coffea) and the cinchona tree (Cinchona).
Mature trees reach a height of 4-16 metres, and in exceptional cases up to 25 metres. The leaves are elliptical, 14-20 cm long, with a pronounced central vein. The colour of this vein (green, white or red) is used in commercial practice as a designation of the raw-material type, although this is a simplification of the botanical and technological background (more in the article Kratom vein colours).
Origin and distribution
The natural range of Mitragyna speciosa covers the tropical regions of Southeast Asia: chiefly Indonesia (particularly the islands of Borneo, Sumatra and Java), Malaysia, Thailand, Myanmar and part of Papua New Guinea. The tree requires a humid tropical climate, well-drained soils and annual rainfall above 1500 mm.
Outside its natural range kratom is grown only marginally and mostly in botanical collections or greenhouse conditions. For commercial leaf production a stable temperature above 20 °C throughout the year is essential - something the temperate zone does not offer.
What kratom contains
The leaves contain more than 40 identified indole and oxindole alkaloids. The dominant one is mitragynine (typically 60-66 % of the total alkaloid content); 7-hydroxymitragynine is present in smaller amounts, along with speciogynine, paynantheine, mitraphylline, speciociliatine and others. The total alkaloid content in the dry leaf usually ranges between 0.5 and 1.8 % by weight.
Besides alkaloids, the leaf also contains flavonoids, polyphenols, terpenoid glycosides and saponins. The proportion of individual compounds differs according to the plant's origin, the age of the leaf and the method of drying and fermentation.
Relationship to coffee and other Rubiaceae
The kinship with coffee within the Rubiaceae family is purely botanical - both the coffee tree and the kratom tree have a similar leaf structure and inflorescence (a spherical head of small flowers), but their alkaloid profiles differ fundamentally. The coffee tree accumulates purine alkaloids (caffeine), whereas the kratom tree accumulates indole alkaloids derived from tryptamine. This relationship is therefore significant from the standpoint of taxonomy, not chemistry or pharmacology.
Frequently asked questions
Is kratom a plant or a chemical substance?
Kratom is plant material - the dried leaf of the Mitragyna speciosa tree. However, the word is also often used for the powder produced by grinding the leaf, or for an extract with concentrated alkaloids.
Does kratom belong with maca, ginseng or coffee?
Botanically, kratom is related to coffee (the Rubiaceae family). Maca belongs to the cabbage family (Brassicaceae) and ginseng to the ivy family (Araliaceae) - so these are unrelated plants.
What is the difference between kratom and mitragynine?
Kratom is plant material (leaf or powder). Mitragynine is one specific alkaloid, the main component of the plant. More in the article Mitragynine: the main alkaloid of kratom.
Does kratom grow in Europe?
Not under Europe's natural conditions. The tree needs a constant tropical temperature and high air humidity, which Central Europe does not provide.
References
- Hassan Z. et al. (2013). From kratom to mitragynine and its derivatives: physiological and behavioural effects. Neuroscience & Biobehavioral Reviews, 37(2), 138-151.
- Cinosi E. et al. (2015). Following "the Roots" of Kratom (Mitragyna speciosa): The Evolution of an Enhancer from a Traditional Use to Increase Work and Productivity in Southeast Asia. BioMed Research International, 2015, 968786.
- Brown P. N., Lund J. A., Murch S. J. (2017). A botanical, phytochemical and ethnomedicinal review of the genus Mitragyna korth. Journal of Ethnopharmacology, 202, 302-325.
