Mitragyna speciosa (commonly known as kratom, also ketum),[2] is a tropical evergreen tree in the coffee family (Rubiaceae) native to Southeast Asia in the Indochina and Malaysia phytochoria (botanical regions). M. speciosa is indigenous to Thailand, Indonesia, and Malaysia, Myanmar, and Papua New Guinea[3] where it has been used in traditional medicine since at least the 19th century.[4] Kratom has some opioid– and stimulant-like properties.[5][6]
As of 2013, no clinical trials had been done to understand kratom’s health effects and it had no approved medical uses.[3][4][7]Some people take it for managing chronic pain, for treating opioid withdrawal symptoms, or – more recently – for recreational purposes.[3][7] Onset of effects typically begins within 5 to 10 minutes and lasts 2 to 5 hours.[3]
Common minor side effects may include nausea, vomiting, and constipation.[3] More severe side effects may include seizure, addiction, and psychosis.[3][8][9][10] Other side effects may include high heart rate and blood pressure, trouble sleeping, and, rarely, liver toxicity.[3][10][11] When use is stopped, withdrawal may occur.[6][7] Respiratory depression (decreased breathing) is a major risk with all opioids;[12]:196 the medical literature is divided on whether it is a significant side effect of kratom, with some authorities not mentioning it[8][11] and others emphasizing it.[9][13] Deaths have occurred when kratom was present, mixed with other substances.[6][7] In the United States, there were fifteen kratom-related deaths between 2014 and 2016,[14] although, in none was kratom thought to be the sole factor.[7]
As of 2015, there was a growing international concern about a possible threat to public health from kratom use.[7][15] In some jurisdictions, its sale and importation have been restricted, and a number of public health authorities have raised alerts.[7][14][15]Sometimes the finished product is mixed into cocktails with other psychoactive drugs such as caffeine and codeine.[6][16]