Mitragyna speciosa trees usually grow to a height of 12–30 ft (3.7–9.1 m) tall and 15 ft (4.6 m) wide, although some species can reach 40–70 ft (12–21 m) in height. Mitragyna speciosa can be either evergreen or deciduous depending on the climate and environment in which it is grown. The stem is erect and branching. The leaves of the kratom tree are a dark green colour and can grow to over 7 inches (180 mm) long and 4 inches (100 mm) wide, are ovate-acuminate in shape, and opposite in growth pattern. The flowers are yellow and round and tend to grow in clusters at the end of the branches. The leaves of M. speciosa are elliptic and are smaller at the end of the branchlets and are pointed at the tip. The leaves have a round and heart-shape at the base with the petioles between 2 to 4 centimeters long. The flowers are crowded in a round terminal inflorescences that are three to five centimeters long. The calyx-tube is short and cup-shaped, with round lobes. The corolla-tube is five millimeters long with three millimeter long lobes and smooth and revolute in between.
There are more than 40 compounds in M. speciosa leaves, including many alkaloids such as mitragynine (once thought to be the primary active constituent), mitraphylline, and 7-hydroxymitragynine (which is currently the most likely candidate for the primary active chemical in the plant), and mitragynine pseudoindoxyl. Other active chemicals in M. speciosa include raubasine (best known from Rauwolfia serpentina) and some yohimbe alkaloids such as corynanteidine.
Mitragyna speciosa also contains at least one alkaloid (rhynchophylline) that is a calcium channel blocker, and reduces NMDA-induced current. The amount of mitragynine within the leaves depends highly on many factors, one major factor is the location of the tree. When trees are grown in Southeast Asia, the levels tend to be higher but when grown elsewhere (even in greenhouses) the levels tend to be low or non-existent. One analysis of products marketed as kratom leaf found, using liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS), mitragynine at levels of 1–6% and 7-hydroxymirtrogynine at levels of 0.01–0.04%. The chemical structure of mitragynines incorporate the nucleus of the tryptamine, and these may be responsible for the molecules observed in the serotonin and adrenergic systems. In mitragynine, the phenolic methyl ether is considered to be stronger in analgesic paradigms according to some studies. Moreover, the pharmacokinetics of M. speciosa in humans has not been well studied and various aspects such as the half-life, protein binding properties and other properties such as the elimination or metabolism is not known.
Kratom was used in Southeast Asia and by Thai natives to substitute for opium when opium was not available. It has also been used to manage opioid withdrawal symptoms by chronic opioid users.
Kratom and its derivatives have been used as substitutes for opium as well as for the management of opium withdrawal. Data on the incidence and prevalence of its use are lacking, as physicians are generally unfamiliar with it, and its use is not detected by typical drug screening tests.
Kratom metabolites can be detected by specialized mass spectrometry tests. Incidence of kratom use appears to be increasing among those who have been self-managing chronic pain with opioids purchased without a prescription and are cycling (but not quitting) their use. As of 2011, there have been no formal clinical trials performed to study the efficacy or safety of kratom to treat opioid addiction.
The pharmacological effects of kratom on humans are not well studied. Its metabolic half-life, protein binding, and elimination characteristics are all unknown.
Kratom behaves as a u-opioid receptor agonist, similar to opiates like morphine, although its effects differ significantly from those of opiates. Kratom does not appear to have significant adverse effects, and in particular appears not to cause the hypoventilation typical of other opioids. Compulsive use has been reported among drug users who inject opioids, and those who use opioids to manage pain without direction from medical professionals.
Kratom has been traditionally chewed, in raw leaf form, by people in Thailand and especially in the southern peninsula. Kratom is often used by workers in laborious or monotonous professions to stave off exhaustion as well as a mood enhancer and/or painkiller. Kratom is also used in neighboring countries in Southeast Asia where it grows naturally. Kratom has been used in Thailand as a form of traditional medicine as an antidiarrheal, as a treatment for opioid dependence as well as premature ejaculation during coitus. As traditionally used, kratom is not seen as a drug and there is often no stigma associated with kratom use or discrimination against kratom users.
In southern Thailand, kratom has been a part of traditional culture for thousands of years and is common in traditional cultural performances and in agriculture. In southern Thailand, kratom chewers generally start at around the age of 25 and many continue to chew the leaves for the rest of their lives. A fresh leaf weighs on average 2 grams. The average number of leaves consumed is between 10 and 60 leaves per day, but even more than this is common. In some areas of southern Thailand, where Kratom is often referred to by the street name P̄hī or 'Goblin', it is thought that upwards of 70% of the male population uses kratom on a daily basis.
The Transnational Institute has argued that while continued research is needed, the criminalization of kratom is unfounded and is based on economic control and disinformation. This group has argued that few records are available showing negative health or social consequences from kratom consumption, but despite this fact kratom is becoming increasingly subject to actions of law enforcement in numerous countries. The criminalization of kratom has created numerous barriers for research. In Thailand, the eradication campaigns have made it especially difficult for academics and researchers to adequately research the medicinal benefits of kratom. This group has concluded that the criminalization of kratom is unnecessary, problematic and counter-productive, and has summarily recommended that kratom be decriminalized. It also concluded that the evidence showing the health benefits of kratom, especially in treating drug and alcohol dependence, should serve as an important point to consider.
Referenced by wikipedia website.