- Kratom; Cratom
- Ketum; Kakuam
- Mitragyne; Mitragyna; Mitragynine
- Thang; Thom
For Patients & Caregivers
Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.
How It Works
Kratom is an herbal supplement that has properties similar to other opioids. It is not recommended as a treatment for pain at this time due to lack of research, harmful side effects, and product contamination.
Kratom is an herbal supplement known to have both stimulant and calming effects. It may also have pain-relieving properties similar to opioids. However, kratom cannot be used as a substitution for prescription pain medications, because studies on its safety or usefulness in humans have not been conducted. Its use is banned in some countries and US states due to potential for abuse. Moreover, some kratom products were recalled due to contamination.
In general there are very limited data on effects in humans for all uses. More research is needed to determine the safety and effectiveness of this herbal supplement.
Although animal studies suggest kratom may relieve anxiety, it may also cause anxiety in humans during withdrawal.
Kratom appears to have sedative effects at higher doses.
Kratom appears to have pain-relieving effects at higher doses.
Lower doses of kratom have been traditionally used for its stimulating effects. It may also cause appetite suppression.
- The FDA recently recalled powdered kratom supplements for salmonella contamination and issued a public health advisory against kratom. It also issued warnings of addiction and overdose risks similar to that of other opioids.
- The Drug Enforcement Administration includes kratom on its Drugs of Concern list. These substances are not currently regulated by the Controlled Substances Act, but pose risks to persons who abuse them. In addition, the National Institute of Drug Abuse identified kratom as an emerging drug of abuse.
Do Not Take If
- You have heart problems: Laboratory studies and case reports suggest kratom could worsen heart problems.
- You are taking CYP450 or UGT substrate drugs: Kratom may affect the clearance of these drugs.
- You are taking P-glycoprotein substrate drugs: When taken with psychoactive drugs that are P-gp substrates, mitragynine may cause significant toxicity.
Withdrawal symptoms: Flu-like symptoms such as nausea, vomiting, chills, sweats, muscle spasms and pain, decreased appetite, or diarrhea; anxiety, irritability, depressed mood, hot flashes, sleeping difficulty. Symptoms are more likely with heavier use.
- Addiction and severe opioid-like withdrawal: In a middle-aged woman who had to be medically treated.
- Overdose and withdrawal: In a young man with no evidence of other drug use.
- Liver damage: From prolonged kratom use.
- Heart attack: In a 26-year-old man. Considered to be caused by kratom as no other cause was identified.
- Cardiac arrest: In a 35-year-old man following kratom use.
- Other fatalities/cardiotoxicities: Involving kratom and mitragynine.
- Deaths: Associated with kratom-containing products or use of multiple drugs in which kratom may have contributed. However, conclusions about which specific drugs caused the deaths could not be determined.
For Healthcare Professionals
Mitragyna speciosa, commonly known as kratom, is indigenous to Southeast Asia. The leaves have been used in traditional medicine to treat pain, fatigue, fever, diarrhea, and wounds (1), while its extracts are known for their psychoactive properties, especially morphine-like effects (2). Kratom has gained popularity as a supplement to improve mood, and decrease anxiety and pain. It has also been a source of significant controversy. The FDA has issued numerous statements against kratom, citing adverse events, potentially related deaths, risk of addiction or overdose, and incidences of contaminated supplements (3) (4) (5).
Kratom has both stimulant and sedative properties (6). The main psychoactive constituents are mitragynine and 7-hydroxymitragynine (7). In vivo studies of derivative compounds and analogs from kratom demonstrate antinociceptive effects (8). Animal models suggest that kratom has muscle relaxant (9), anti-inflammatory (10), analgesic (11), and anorectic (12) properties. Mitragynine has also shown antioxidant and antiproliferative effects in a few cancer cell lines (13).
Data on the use and safety of kratom in humans are very limited. Stimulant effects occur at lower doses, while sedative and pain-relieving effects occur at higher doses (14). Kratom users may develop physiological dependence and experience withdrawal (15), but this risk has not yet been adequately quantified (16). More research on the therapeutic uses for kratom and its constituents, as well as its toxic effects and abuse potential is needed.
The biological activities of kratom in humans are still poorly characterized (17). Because of its potential interactions with other drugs (18) (19) and possible side effects (20), kratom should not be used as a substitution for prescription pain medications. Several countries and US states have banned the use of kratom due to its potential for abuse (21) (22).
Mechanism of Action
The main active alkaloids in kratom are mitragynine; and 7-hydroxymitragynine (7-HMG), which is thought to have analgesic effects comparable to morphine (11) (23). Through monoaminergic and opioid receptors, both compounds produce a range of CNS stimulant and depressant effects (23) (24) (25).
Although structurally different (26), mitragynine administration causes cognitive impairment and addiction profiles that closely resemble those of morphine (27). Other research also suggests these compounds share classic opioid characteristics—affinity for opioid receptors, analgesic cross-tolerance, and competitive interaction with naloxone–while possessing other novel attributes (28).
- The FDA recently recalled powdered kratom supplements for salmonella contamination (5) and issued a public health advisory against kratom (3), with warnings of addiction and overdose risks similar to that of other opioids (4).
- The Drug Enforcement Administration includes kratom on its Drugs of Concern list. These substances are not currently regulated by the Controlled Substances Act, but pose risks to persons who abuse them. In addition, the National Institute of Drug Abuse identified kratom as an emerging drug of abuse (31).
- Herbal mixtures that contain synthetic compounds and kratom have been linked to altered behavior (32), hemorrhagic stroke (45) and multiple deaths (33).
Withdrawal symptoms: Flu-like symptoms such as nausea, vomiting, chills, sweats, muscle spasms and pain, decreased appetite, or diarrhea; anxiety, irritability, depressed mood, hot flashes, sleeping difficulty; symptoms are more likely with heavier use (15) (16) (35).
Addiction and severe opioid-like withdrawal syndrome: In a 37-year-old woman who was treated with clonidine and hydroxyzine (36).
Overdose and withdrawal: In a young man with negative toxicology screens (14).
Liver injury: From prolonged kratom use (37) (50) (51).
Cardio-respiratory arrest: In a 26-year-old man and considered a direct result of kratom ingestion in the absence of other identified causes (38).
Cardiac arrest: In a 35-year-old man following kratom use (49).
Other fatalities/cardiotoxicities: Involving kratom and mitragynine (34) .
Deaths: Associated with the use of kratom-containing products or polydrug use in which kratom was suspected to have possibly contributed (3) (39) (40) (33) (41) (31) (46) (47) (48). The multi-drug circumstances confound conclusive interpretation (42).
- Cytochrome P450 (CYP 450) substrates: Increased clearance of drugs metabolized by CYP450s (18) (19) . Kratom may also inhibit CYP2D6 (43), and induce CYP1A2 (44).
- UGT (Uridine 5’-diphospho-glucuronosyltransferase) substrates: Increased clearance of drugs metabolized by UGT1A6 with kratom use (18).
- P-glycoprotein substrates: Mitragynine inhibits P-gp in vitro, and concurrent administration with psychoactive drugs that are P-gp substrates may cause significant toxicity (52).