Kratom refers to the plant Mitragyna speciosa Korth., a tree
indigenous to Thailand; it is mostly grown in the central
and southern regions of the country, and only rarely in the
north. The Mitragyna genus, part of the family Rubiaceae,
is found in tropical and sub-tropical regions of Asia and
Africa. Asian Mitragynas are often found in rainforests,
while the African species (which are sometimes still classed
in a separate genus, Hallea) are often found in swamps.
Most species are arborescent, some reaching heights of
almost 100 feet. The genus was given its name by Korthals
because the stigmas in the first species he examined
resembled the shape of a bishop's mitre. This genus is
characterized by a globular flowering head, bearing up to
120 florets each. During the flower bud stage, the
developing florets are surrounded and completely covered
by numerous overlapping bracteoles. Mitragyna species are
used medicinally as well as for their fine timber through the
areas they grow.
Mitragyna speciosa itself reaches heights of 50 feet with a
spread of over 15 feet. The stem is erect and branching.
Flowers are yellow. Leaves are evergreen, and are a
dark glossy green in color, ovate-acuminate in shape,
and opposite in growth pattern. Kratom is evergreen
rather than deciduous, and leaves are constantly being
shed and being replaced, but there is some quasiseasonal leaf shedding due to environmental
conditions. During the dry season of the year leaf fall is
more abundant, and new growth is more plentiful
during the rainy season. When grown outside their
natural tropical habitat, leaf fall occurs with colder
temperatures, around 4 degrees Celsius.
Kratom prefers wet, humusy soils in a protected position.
Being a heavy feeder, it requires very rich, fertile soil. It
is drought sensitive, and if grown out of its native
habitat, sensitive to frost. Propagation is by very fresh
seed or cuttings. There is a low strike rate, due to an
endogenous fungus which attacks xylem tissue.
Over 25 alkaloids have been isolated from kratom.
The most abundant alkaloids consist of three indoles
and two oxindoles. The three indoles are mitragynine,
paynanthine, and speciogynine - the first two of
which appear to be unique to this species. The two
oxindoles are mitraphylline and speciofoline. Other
alkaloids present include other indoles, and
oxindoles such as ajmalicine, corynanthedine,
mitraversine, rhychophylline, and stipulatine.
Mitragynine is the dominant alkaloid in the plant. It was
first isolated in 1907 by D. Hooper, a process repeated
in 1921 by E. Field who gave the alkaloid its name. Its
structure was first fully determined in 1964 by D.
Zacharias, R. Rosenstein and E. Jeffrey. It is
structurally related to both the yohimbe alkaloids and
voacangine. It is more distantly related to other
tryptamine-based psychedelic drugs such as psilocybin
or LSD. Chemically, mitragynine is 9-methoxycorynantheidine. It has the molecular formula
C23H30N2O4 and a molecular weight of 398.5.
Physically the freebase is a white, amorphous powder
with a melting point of 102-106 degrees and a boiling
point of 230-240 degrees. It is soluble in alcohol,
chloroform and acetic acid. The hydrochloride salt has a
melting point of 243 degrees.
The alkaloid content of the leaves of Mitragyna speciosa is
about 0.5%, about half of which is mitragynine. An
average leaf weighs about 1.7 grams fresh or 0.43 grams
dried. Twenty leaves contain approximately 17mg of
mitragynine. All leaves appear to contain mitragynine,
speciogynine, paynanthine, and small quantities of
speciociliatine. Oxindole alkaloids usually occur only in
small or trace ammounts.
Alkaloid content varies from place to place and at
different times. Within each location, there is a
quantitative variation in alkaloid content from month to
month. While indole content seems to be fairly stable,
oxindole content shows tremendous variation.
Kratom is traditionally only used in Thailand, although
some use in Malaysia has been reported. Besides
kratom (or krathom), it also goes by the names ithang,
kakuam, and in southern regions, thom. Use dates far
enough back that its beginning can't be determined. In
addition to being used as a narcotic drug in its own
right, it is often used as a substitute for opium when
opium is unavailable, or to moderate opium addiction.
In folk medicine, it is often used to tread diarrhea. A
small minority of users use kratom to prolong sexual
Users distinguish different types of kratom, two main
kinds being distinguished by the color of veins in the
leaf - red or green/white. The green-veined variety is
supposed to have a stronger effect. One study which
surveyed Thai kratom users found that most users
preferred a mixture of both, followed by red-veined
alone and then white-veined alone. Growers in
Australia report that both red and white veining occurs
at different times in different plants which were all
cloned from the same mother plant. They have not yet
undertaken comparisons between the two.
Nearly all kratom use is by chewing fresh leaves. Other
ways it is taken include grinding up and eating fresh,
dried, or reconstituted dried leaves. Some villagers use
the leaves in cooking. When preparing fresh leaf, the
vein is extracted and sometimes salt is added to try and
prevent constipation. Consumption of the leaf is usually
followed by drinking something hot, such as warm
water or coffee. Leaves can also be smoked, made into a
tea, or a crude resin extraction can be made. This resin
extract is made by preparing a water extract of the
leaves, boiling it down, and then shaping it into small
balls which are rolled in a material such as flour, then
stored until use. This is apparently a quite popular
method of consumption.
Users of kratom tend to be peasants, laborers, and
farmers who use the plant to overcome the burdens of
their hard work and meager existences. Female users
are apparently quite rare. Age of usage onset seems to
be higher than for other drugs. Some studies have found
no addiction problems in villagers using kratom, while
others apparently have. It seems likely that if used in
doses high enough for mu receptor crossover (discussed
below), addiction is a strong possibility. Heavy users
may chew kratom between 3 and 10 times a day. While
new users may only need a few leaves to obtain the
desired effects, some users find with time they need to
increase doses to 10-30 leaves or even more per day.
The Thai government passed the Kratom Act 2486 which
went into effect on August 3, 1943. This law makes
planting the tree illegal and requires existing trees to be
cut down. This law was not found effective, since the
tree is indigenous to the country. Today, kratom is
classed in the same enforcement group as cocaine and
heroin by Thai law, and has the same penalties. One
ounce of extract is punishable by death. As with
prohibition laws elsewhere in the world, this has
succeeded only at increasing black market prices. A
related species, Mitragyna javanica, is often used as a
substitute to get around the law, but it is not considered
as effective. The dominant alkaloid in this species is
mitrajavine, which has not yet been pharmacologically