Kratom, formally named Mitragyna speciosa and Mitragyna speciosa korth, is a tropical member of the coffee family. This evergreen tree grows naturally in Myanmar, Thailand, Malaysia, and other parts of South Asia.

People sometimes use kratom leaves, or extracts made from them, as a sedative, stimulant, or both. In use throughout Southeast Asia for hundreds of years, kratom is also used to treat opiate withdrawal, digestive ailments, and chronic pain. However, reliable information about Kratom is not easy to find.

Kratom is easy to order on the internet and is not currently an illegal substance. It is often sold as a gum or an extract, or as a powder in teas, packets, or capsules. Sometimes the leaves themselves are sold, of course.

What Is Kratom

Kratom is the common name for the tropical tree named Mitragyna speciosa, an evergreen member of the coffee family. Native to Southeast Asia, it has been used in herbal medicine in Myanmar, Indonesia, Papua New Guinea, Malaysia, and Thailand, where it grows wild, since at least the nineteenth century. Kratom has both stimulant-like and opioid effects.

Street names for kratom include biak, kakuam, ketum, thang, and thom.

A 2018 research review of work on kratom concluded that the poor quality of the research into the substance’s safety and efficacy preclude approval as a therapeutic agent. Since 2019, the United States Food and Drug Administration (FDA) has warned US consumers not to use kratom, indicating that there is no evidence that it is safe or effective to treat any disease or condition with the plant.

However, as the Research section below indicates, the latest research into kratom is very promising.

Perhaps this is why kratom is trending, although people take it for different reasons. Some use kratom recreationally, and many others use it to treat opioid withdrawal symptoms, or to manage chronic pain. Expect the effects from kratom to start within several minutes of using it, and last for two to five hours.

Users report a number of effects from kratom, including:

  • increased alertness
  • sociability, talkativeness
  • mood changes
  • more physical energy
  • sedation
  • pain relief

Possible side effects from kratom include

  • appetite loss
  • constipation
  • erectile dysfunction
  • hair loss
  • addiction
  • decreased breathing/respiratory depression
  • difficulty sleeping
  • high blood pressure
  • high heart rate
  • psychosis
  • seizure
  • liver toxicity (rare)
  • death

But see our detailed discussion of this below.

Withdrawal symptoms may occur when use is stopped. Kratom alone or mixed with other substances has caused death, although rarely. Serious toxicity typically appears when kratom is used with other substances and/or at very high doses and is relatively rare.

A controlled substance in at least 16 countries, the FDA has banned the manufacture and import of kratom as a dietary supplement.

Kratom Tree Appearance and Description

The evergreen tree Mitragyna speciosa can reach a height of 82 feet or 25 meters. Trees that reach those heights may have trunks that are 3 feet or almost a meter in diameter.

Pieter Korthals, a Dutch colonial botanist, first formally described the kratom tree in 1839. He named the plant Stephegyne speciosa, but it was reclassified and renamed several times before its final name and classification in 1859 as Mitragyna speciosa, provided by George Darby Haviland.

The trunk of the kratom tree is generally tall, long, and straight, with smooth, gray outer bark. Kratom leaves on the tree are glossy and dark green. The ovate-acuminate shaped leaves can reach sizes of over 5.5 to 7.9 inches long and  2.8 to 4.7 inches wide when opened fully. Leaves have 12 to 17 pairs of veins running through them which take on different colors. Deep yellow kratom flowers grow at the ends of the branches in clusters of three.

Use of Kratom

As explained above, since 2019, the FDA has warned US consumers not to use kratom at all. That said, people can and do use kratom, both in traditional and modern ways.

People often use kratom leaves by chewing them, or by making them into tea. Kratom leaves are also or extracted into powder for other uses. Kratom is smoked only rarely.

Traditional use

kratom powder and capsules

In cultures where the kratom thrives natively, it is often part of traditional practices and seen as a medicinal herb. Kratom was recorded as a substitute for opium in Malaysia in 1836, and it was also used this way in nineteenth century Thailand.

Much like coca or khat, people chew kratom leaves to increase appetite, energy, and sexual desire, and to relieve musculoskeletal pain. Kratom extracts and leaves are used as a local anesthetic, to heal wounds, as intestinal deworming agents, and to treat diarrhea, coughs, and gastrointestinal infections.

In dull, difficult, and dangerous professions, workers often use kratom to enhance the mood, ward off pain, and stave off exhaustion. In fact, kratom had much higher traditional status in Thailand, and was seen as a treat for the ritual worship of gods and ancestors and receiving honored guests. Generally, even traditional users of kratom find it bitter and consume it with some sort of sweetener.

Today, it is legal for households in Thailand to grow up to three kratom trees each, and the substance is no longer considered a narcotic. The main locus of the controversy is the United States.

Opioid withdrawal

A 2021 study which analyzed YouTube user videos on kratom use found that the vast majority of people use kratom to manage opioid addiction and symptoms of opioid withdrawal. Another 2021 study has found that kratom alkaloids do ameliorate opioid withdrawal in mice. However, kratom is still not approved for this use, nor any other medical application, in the US.

Even so, many people are willing to try kratom, in part because traditional opioids are so dangerous, and in part because the withdrawal effects of kratom are typically less severe than those associated with traditional opioids. Research indicates that kratom can induce physical dependence but has less potential to do so. Kratom is also far less likely to cause death, and most kratom overdose cases are related to either polysubstance use or poorly sourced material.

Data on worldwide kratom use is lacking. However, as of 2021, in the United States less than one percent of people use kratom, although 10.3 percent of people with opioid use disorder use it.

Recreational uses

At lower doses, kratom’s effects are similar to coca, with users describing alertness, increased sexual desire and work capacity, positive mood, sociability and talkativeness, and euphoria. At higher doses, kratom’s effects are much more like those of opioids, which is why it is such a popular choice for withdrawal symptoms—although treating anxiety, pain, and depression are also popular goals. Kratom effects generally start within five to ten minutes of taking it and last for up to five hours.

A 2007 survey of respondents aged 12 to 65 years in Thailand found that the lifetime, past year, and past 30 days’ rates of kratom use were 2.32 percent, 0.81 percent, and 0.57 percent, respectively, making kratom the most widely used drug in the country.

Kratom can and sometimes is mixed with other psychoactive drugs, such as codeine and caffeine—although this can be more dangerous. For example, a tea-based cocktail of kratom leaves, Coca-Cola, cough syrup, and ice called 4×100 has become popular in some parts of Thailand and Southeast Asia.

In the US, as of this writing, kratom is illegal in six states: Alabama, Arkansas, Indiana, Rhode Island, Vermont, and Wisconsin. It is explicitly legal in Arizona, Georgia, Nevada, and Utah. It is not regulated but still technically legal at the federal level, so everywhere else it is basically the same. In most places where it is not explicitly illegal, it is sold online and in head shops.

From 2011 to 2017, kratom use was on the rise. An estimated 0.7 percent of the United States general population of adults and adolescents use kratom as of 2021—that’s over 2.3 million people.

How to Use Kratom Powder

There are several ways to use kratom powder. Kratom powder can be used to brew tea. This is a traditional method that is still popular, and this way you can choose the basic tea you already like and then just add kratom powder, honey, lemon, whatever you enjoy.

Smoothie, Juice, or Protein Shake

Since kratom has a distinct, bitter, plant-y taste, many people enjoy kratom powder more in dietary ingredients that mask the taste somewhat, like a glass of fruit juice, or for more active pople, a protein shake or smoothie.


The easiest way to get your kratom powder in the exact right dose is in capsules.

Research on Kratom

Kratom is under research for a range of uses, including in psychiatry thanks to possible antidepressant and antipsychotic properties, and treatment for acute and chronic pain, opioid use disorder, and various mental health conditions, including depression and anxiety. Scientists are also hoping to develop novel drugs based on kratom’s molecular structure that might treat alcohol use disorder, opioid use disorder, and pain more effectively.

A 2010 report in the International Journal on Drug Policy surveyed 136 active kratom users in Malaysia, The kratom users reported that it was readily available, affordable, and that even with prolonged use kratom had no serious side effects, but the researchers stopped with the survey. In other words, they did not test potential risks or health effects.

However, a 2014 survey of 293 regular kratom users published in Drug and Alcohol Dependence found that over half of the kratom users developed severe problems with dependence and kratom withdrawal symptoms including anger, sleep disruption, muscle spasms, and tension.

A 2016 study conducted on mice and published in the Journal of Medicinal Chemistry found that unlike other pain-relieving drugs such as morphine, kratom may not slow breathing as much. As respiratory depression is a leading cause of death during opioid overdoses, the researchers suggest that analogs may be part of a novel class of pain relievers, warranting further research.

A 2017 study in the Journal of Drug and Alcohol Dependence surveyed 10,000 current kratom users in the US in October of 2016. The researchers found that the main population of US kratom users were 31 to 50 years old with incomes of at least $35,000. They mainly used kratom for mood swings, pain, and opioid-related withdrawal symptoms, and 40 percent of respondents discussed their kratom use with their healthcare provider or other health care professionals. For both beneficial and negative symptoms there was a possible dose-dependent effect, and a low incidence of kratom-related toxicity requiring treatment of 0.65 percent.

Research into the potential for abuse of kratom from 2018 found that there was no documented threat to public health that would warrant emergency Schedule I status for kratom products, and such classification within the Controlled Substances Act itself carries risks of creating new and serious public health issues. The researchers also concluded that to ensure safe and appropriate use of kratom, appropriate FDA regulation would be vital.

Another Journal of Drug and Alcohol Dependence study, this time from 2018, conducted a systematic, comprehensive review of all studies of mental health and kratom use from 1960 to July 2017—for them, the present. They found that kratom has high potential as a harm reduction tool, particularly for people addicted to opioids. The researchers also found that kratom relieves anxiety and enhances mood among many users. Finally, they concluded that relative to those of opioids, kratom’s withdrawal symptoms appear to be mild, and that these symptoms are the lion’s share of kratom’s negative mental health effects, although abstinence can be difficult and withdrawal is highly uncomfortable for some users.

A 2018 study in Pharmacology presented a more complete pharmacological profile than we’d seen to date on this plant and its active ingredients. The researchers confirm that kratom leaves contain alkaloids which bind with opioid receptors, which explains the opiate-like effects of the plant. However, the 7-hydroxy- and mitragynine do not facilitate β-arrestin binding with the mu-opioid receptor, and for various reasons kratom and its alkaloids do not cause the kind of significant respiratory depression that makes opioids so dangerous. The researchers found that kratom is used as mood enhancer, as an analgesic, and to treat symptoms of opioid withdrawal. Finally, the team confirms the dose-dependent effects of kratom, with low doses of kratom causing stimulant effects and high doses causing analgesic effects.

However, a 2019 study in Pharmacotherapy reviewed kratom exposures reported by poison centers to the National Poison Data System and records from a county medical examiner’s office in the State of New York to identify deaths associated with kratom and determine toxicities associated with kratom use. They identified a total of 2,312 reported kratom exposures, with 935 cases involving only kratom reported. Most common reported effects were less serious, but serious effects were also reported, including withdrawal (6.1 percent), seizures (6.1 percent), and hallucinations (4.8%).

Contrary to other findings, this team reports respiratory depression (2.8%), coma (2.3%), and cardiac or respiratory arrest (0.6%), but they also report only four deaths where kratom was listed as a contributing factor or cause. This leads us to conclude that their numbers do in fact include polysubstance and adulteration cases, bringing their findings, if not their conclusions that kratom poses a public health threat, into line with other results. However, it is a very useful compilation of a wide range of potential side effects that could be related to kratom.

An article from authors engaged in various aspects of kratom research, also from 2019, concluded that both animal and human studies “strongly suggest” that mitragynine, the main constituent alkaloid of kratom, and the plant itself, may manage symptoms of opioid withdrawal and alleviate pain. There are real concerns about how safe and high-quality imported kratom products are, but only more research and regulation can resolve them. Classification of kratom and the Mitragyna alkaloids as Schedule I controlled substances would only make these issues worse.

Results from a 2019 analysis of a 2017 online survey of 2,867 current users and 157 former users of kratom reported that kratom users often use the substance to treat conditions in place of opioids, including to treat pain and reduce existing opioid use. Users report high efficacy and a low incidence of adverse reactions to kratom, especially compared to opioids. The researchers conclude kratom may offer an alternative to opioids for some and suggest further study.

A 2020 National Institutes of Health study found opioid-like effects from kratom and suggested it may have a role to play in fighting the opioid epidemic.

A 2020 study in Drug and Alcohol Dependence reported on a cross-sectional, anonymous online survey that was conducted of 2,798 kratom users in 2017, almost entirely located in the US. The researchers concluded that middle-aged white Americans are the most frequent users of kratom, and that these users are treating symptoms of anxiety, pain, depression, and opioid withdrawal. Most are not using kratom as a recreational drug. Serious kratom-related adverse effects and SUD were rare despite regular use, which was typical. The team concludes that in light of the present opioid epidemic, additional research on kratom pharmacology and epidemiology is imperative.

A 2020 short report in Addiction endeavored to describe past-year prevalence of kratom use and characterize kratom users by using results from the Cross-sectional Survey of Non-medical Use of Prescription Drugs (NMURx) Program from parts of 2018 and 2019 and estimating behavior proportions. They estimated the past-year prevalence of kratom use in the US at 0.8 percent, and found that kratom users tended to have more serious substance abuse profiles than users of cannabis, alcohol or cigarettes, or non-users.

However, a response from January 2021, also in Addiction, calls the 2020 short report’s characterization misleading and argues they may be misinterpreted to support the notion that kratom use increases the risk of abusing other drugs, or to infer a cause-effect relationship between substance-use disorders and kratom use—neither of which exist. The authors argue that the current weight of evidence shows that kratom use tempers more problematic use of other more dangerous substances, and that its risks are substantially lower than those other drugs.

Finally, a 2020 study in Nature presented chemical profiles of 53 commercial kratom products to better assess their safety and efficacy in treating pain. The study demonstrates that kratom alkaloids have unique binding and functional profiles, suggesting probable pain management benefits. However, the team also found that all three tested kratom alkaloids inhibit select cytochrome P450 enzymes, suggesting a potential risk from polysubstance consumption when kratom is consumed with drugs metabolized by these enzymes. The researchers point out that further studies are needed.

A January 2021 study in Cellular and Molecular Biology tested claims of kratom’s effectiveness against opioid dependence and withdrawal by evaluating the ability of chronically administered kratom in several forms to induce hyperalgesia and produce physical dependence. The team tested a blended extract of kratom alkaloids and the individual alkaloids mitragynine (MG) and its analog mitragynine pseudoindoxyl (MP), in morphine-dependent mice. They suggest “some clinical value,” finding that all three ameliorated precipitated withdrawal and produced significantly less physical dependence in morphine-dependent mice.

A March 2021 study in Substance Abuse Treatment, Prevention, and Policy assessed the quality of available information on 51 eligible kratom websites in Canada. They found that overall mostly poor quality consumer health information was available online, with 78 percent of vendors getting 2 or less out of 5 as their score. They conclude that better information for consumers could improve health outcomes in Canada.

A study in the September 2021 Journal of Drug and Alcohol Dependence analyzed user-generated social media Reddit posts from 42 subreddits between June 2019–July 2020 to gain a more nuanced view into kratom use patterns and determine if descriptive, independent accounts mostly line up with prior findings from surveys of US kratom users. Results validated many prior survey findings and supported continued investigation. For example: kratom was often used as an opioid substitute or to self-treat opioid withdrawal; polydrug use with kratom was common; users perceive kratom as both lifesaving and potentially addictive and describe symptoms of kratom dependence and withdrawal in detail; and most kratom users are patients with pragmatic goals, not recreational users.

The bottom line here is that the latest research into kratom reveals that, although much more work remains, it is a much less risky substance than anything it replaces. Using safely-sourced kratom wisely is a low-risk activity for most people.

For a complete reference list with DOIs see end of paper. 

Kratom Side Effects

Mitragyna speciosa may cause side effects, some of them more adverse than others. However, the nature and extent of these side effects remains in dispute.

In November 2017 the FDA issued a public health advisory urging citizens to avoid using kratom entirely. In 2018, FDA Commissioner Scott Gottlieb issued a statement underscoring kratom’s potential for abuse. However, side effects connected to kratom appear to be dose-dependent, with higher doses exceeding 8 grams producing more frequent adverse effects.

A comprehensive set of numbers for adverse side effects in kratom users is unknown. However, a 2019 review in Pharmacotherapy of kratom exposures reported over a seven-year period to US poison control centers along with several other recent studies (cited above) list these possible adverse side effects from kratom—alone in some cases, used with other drugs in other cases:

  • agitation
  • anorexia
  • blushing
  • calmness
  • confusion
  • constipation
  • contracted pupils
  • decreased appetite
  • delusions
  • drowsiness
  • dry mouth
  • euphoria
  • hair loss
  • hallucinations
  • high blood pressure
  • hyperpigmentation/discoloration of the cheeks
  • increased social behavior
  • increased urination
  • insomnia
  • irritability
  • itching
  • nausea
  • palpitations
  • poor concentration
  • sensitivity to sunburn
  • sweating
  • tachycardia
  • talkativeness
  • temporary erectile dysfunction
  • tremor
  • vomiting
  • weight loss
  • withdrawal

And these symptoms have been reported by kratom users, but it’s unclear that any of these are actually directly attributable to kratom use:

  • hepatitis
  • hypothyroidism
  • psychosis
  • respiratory depression
  • seizure
  • coma
  • cardiac or respiratory arrest
  • death
  • neonatal abstinence syndrome

Risks from higher potency concentrated extracts appear to be higher, and risk also increases when kratom is mixed with other drugs, psychoactive substances, or adulterants, or when people with a history of heroin use, alcohol use disorders, or some health problems take it.

Kratom products with 2 to 6 grams of dried leaf per dose are most commonly used in the US, with doses over 8 grams being fairly unusual. However, the potency of kratom products often varies greatly as there are no standards for dosing.

There are mostly stimulant effects resembling those of coca products at relatively low doses—those would be 1 to 5 grams of raw leaves. Kratom side effects at low doses include blushing, contracted pupils, and adverse stimulation effects such as agitation and anxiety. At low doses kratom may also produce opioid-related side effects such as nausea, itching, loss of appetite, and increased urination.

More prominent opioid effects generally appear at moderate to high doses of kratom, typically 5 to 15 grams of raw leaves. At these moderate to higher doses, users risk additional adverse stimulant and opioid side effects such as constipation, dizziness, dry mouth, hypotension, sweating, and tachycardia.

Repeated use of high doses of kratom over the long term may lead to development of dependence, tolerance, and symptoms of withdrawal upon stopping, including weight loss, loss of appetite, trouble sleeping, decreased sexual drive, muscle and bone pain, muscle spasms, jerky movement, hot flushes, watery eyes, diarrhea, fever, anger, restlessness, and sadness. The difficulty of enduring these kinds of symptoms can cause people to start using again, even if they’d rather not.

There are a few other risks to keep in mind based on the research on kratom we cited:

  • Frequent use of high doses of kratom may cause tremors, anorexia, weight loss, and seizures.
  • There are reports that high and frequent doses of kratom is associated with psychosis as well, but it is unclear whether kratom use revealed existing psychosis or directly caused the condition.
  • Serious toxicity is rare and typically occurs when kratom is used with other substances, at high doses, or when both conditions are met.
  • Kratom mixed with other substances—legal and illegal—may cause herb-drug interactions, including alcohol, benzodiazepines, caffeine, cocaine, monoamine oxidase inhibitors (MAOIs), opioids, sedatives, or yohimbine.

Can You Overdose on Kratom?

Although multiple death reports mention ingestion of kratom, the vast majority of these involve other substances. A 2019 paper analyzed National Poison Data System data and found that there were only 11 deaths even linked to kratom exposure between 2011 and 2017, and nine of the 11 deaths involved kratom and other medicines or drugs, such as alcohol, diphenhydramine (an antihistamine), benzodiazepines, caffeine, cocaine, and fentanyl.

The FDA identified at least 44 deaths related to kratom by 2018, with one possible pure kratom case among them. The FDA findings indicate that many of the kratom-associated deaths were caused by taking kratom with other potent substances, including alcohol, benzodiazepines, gabapentin, illicit drugs, opioids, and OTC medications such as cough syrup, or by taking adulterated kratom products. The FDA also found reports of kratom laced with other deadly compounds.

Medical teams manage kratom overdoses similarly to opioid overdoses, and despite mixed results for its utility, naloxone can be used to treat an overdose that results in respiratory depression.

In 2017 and 2018, 28 people in the US were infected with a multistate outbreak of salmonella from using contaminated kratom. According to whole genome sequencing, a common kratom source probably caused the salmonella outbreak.

Respiratory depression

The leading risk of death from opioid use, respiratory depression from taking Mitragyna speciosa appears to be low. A 2018 study found that kratom and its active ingredients do not cause the kind of significant respiratory depression that makes opioids so dangerous. However, the FDA continues to list respiratory depression as a risk or area of concern regarding kratom.

Liver toxicity

Kratom has been connected to rare instances of acute liver injury that are clinically apparent. Symptoms include pruritus, nausea, fatigue, and dark urine with jaundice as the last appearing symptom.


Most kratom related deaths involve other substances. That 2019 paper on National Poison Data System data we mentioned above found only two deaths that might have been solely caused by kratom—and that link was not proven.

Chemistry and Pharmacology of Kratom

Kratom is an agonist that binds to the brain’s mu-opioid receptors, those that are activated by opioids such as heroin or prescription painkillers. In that sense, kratom is a natural opioid, and although its structure mitigates against some of the work risks that all opioids carry with them—it does carry inherent risk of tolerance, dependence, and withdrawal.

Kratom Chemistry

Many of Mitragyna speciosa’s main psychoactive compounds are indole alkaloids related to mitragynine. The alkaloid mitragynine is tetracyclic, similar to the indole alkaloids voacangine and yohimbine which are pentacyclic.

Significant proportions of the isolable natural products that occur in Mitragyna speciosa are composed of mitragynine and 7-hydroxymitragynine (7-HMG). Mitragynine makes up 12 to 66 percent of leaf source weight depending on whether the leaf sources are Malaysian or Thai, and 7-hydroxymitragynine constitutes around 2 percent by weight.

Scientists have also isolated at least 40 other compounds from kratom leaves, including approximately 25 additional alkaloids. Among those are corynantheidine, also found in Pausinystalia johimbe; raubasine/ajmalicine, isolated originally from Rauvolfia serpentina; as well as mitragynine pseudoindoxyl, mitraphylline, and rhynchophylline.

Mitragyna speciosa produces various other secondary metabolites in addition to alkaloids. These include triterpenoids such as oleanic acid and ursolic acid; various iridoids, saponins, and other monoterpenoids; as well as various polyphenols including quercetin and apigenin, which are flavonoids. Some of these compounds possess anti-inflammatory, antinociceptive, antioxidant, antidepressant, antibacterial, and gastrointestinal effects in cells and in animals.

How Long Does Kratom Stay In Your System?

Kratom’s precise half-life is still uncertain; more research will be needed to determine that number. Several factors influence how long kratom stays in your system, as is true for other substances. Some of the most important are biological factors about the user such as age, genetics, body fat, and metabolic rate; lifestyle factors such as frequency of use, and intake of food and water; and source factors such as the type of kratom and the dose.

Detection of kratom in body fluids

Typical drug screening panels do not detect the plant’s metabolites and active compounds, but more specialized testing can detect them. Liquid chromatography-mass spectrometry is the most common means to detect kratom (or its results) in body fluids. Most testers expect blood mitragynine concentrations in recreational users to range from 10 to 50 μg/L.

Pharmacology and Toxicology of Kratom

There are at least 40 alkaloids in kratom, including: mitragynine, 7-hydroxymitragynine (7-HMG), corynantheidine, mitragynaline, mitraphylline, paynantheine, rhynchophylline, mitralactonal, raubasine, speciociliatine, and speciogynine. Although most kratom’s complex effects are produced by the alkaloids mitragynine and 7-hydroxymitragynine, the other alkaloids may help to create a sort of synergistic effect that does contribute.

Both mitragynine and 7-HMG are competitive antagonists of the δ-opioid receptor and partial agonists of the μ-opioid receptor, with low affinity for the κ-opioid receptor. Both readily cross the blood-brain barrier. Mitragynine appears to have lower affinity at the μ-opioid receptor than 7-HMG. These compounds do not activate the β-arrestin pathway as they are functionally selective, so they are less likely to cause side effects associated with traditional opioids such as constipation, respiratory depression, and sedation.

Mitragynine inhibits block L-type, COX-2, and T-type calcium channels. Mitragynine also interacts with other brain receptors including D2 dopamine receptors, serotonin receptors 5-HT2C and 5-HT7, and A2A adenosine receptors.

However, perhaps because mitragynine stimulates α2-adrenergic receptors, which inhibits the release of norepinephrine, kratom used in combination with other sedatives can be dangerous. Other compounds in this class include clonidine, prescribed to manage some symptoms of opioid withdrawal and anxiety, and dexmedetomidine, used for sedation. Kratom also contains the non-competitive NMDA receptor antagonist rhynchophylline, perhaps in response to this activity.

Humans metabolize mitragynine via phase I and phase II mechanisms, and users excrete metabolites in urine.

Regulation of Kratom

Neither kratom nor its active ingredients, the alkaloids, were listed in the schedules of the United Nations Drug Conventions.

ASEAN and Asia

The 2019 ASEAN Drug Monitoring Report lists kratom among “New Psychoactive Substances” or NPS in line with the 2013 2013 World Drug Report. That report found that kratom accounted for most NPS seizures.

Malaysia and Myanmar still control kratom as a substance, while it is now legal in Thailand. In 2022, kratom is scheduled to become an illegal substance in Indonesia.

Australia and New Zealand

Kratom is considered a narcotic and a controlled substance in Australia and in New Zealand.


In 2020, Health Canada warned the public about ingesting kratom and disallowed marketing of kratom products—unless they are for other uses, such as incense.


Kratom is controlled in Latvia, Denmark, Poland, Lithuania, Sweden, and Romania. The Republic of Ireland designated kratom a Schedule I illegal drug in 2017, under the names mitragynine and 7-hydroxymitragynine.

United States

The debate over listing kratom as a Schedule I drug continues. In 2014, the FDA issued an import alert for kratom. Since 2019, the US Food and Drug Administration has warned consumers generally not to use kratom, that kratom in commercially available products may be unsafe, that these products remain unapproved for interstate commerce, and may be confiscated.

Also in 2019, the CDC waded into the kratom issue with a case report on unintentional overdose deaths with connections to kratom. The Drug Enforcement Administration or DEA has also made moves to schedule kratom, but thus far has failed—in part due to an ongoing inability to prove that kratom and drug abuse are linked.

However, as discussed above, recent research reveals exciting therapeutic possibilities. Alongside anecdotal evidence and surging need, scheduling efforts directed toward kratom continue to fuel notable controversy among both the scientific community and the general public.


The sale, export, and import of kratom are prohibited in the UK under the Psychoactive Substances Act.

What Are Kratom Products Made Of?

Kratom products are made from leaves of the Mitragyna speciosa tree—an evergreen grown primarily in Indonesia, and a distant cousin to coffee. Sometimes the Kratom tree’s leaves are chewed directly by whoever harvests them, but more commonly they are sold or processed and sold as capsules, as tea, or as powder—all natural herbal products.

All the Kratom bought and sold in the US originates in Indonesia. For the most part, it is harvested in the rural villages of Borneo by local people near wild Kratom trees who sell at market or who work privately owned land. Tropical regions offer friendly conditions for wild growth of kratom trees, which can reach 80 feet or higher in these areas.

What are Kratom Strains?

Unfortunately, much like lore versus science when it comes to cannabis strains, there is little science to back up anecdotes about kratom vein colors. Many users—and even more sellers hoping to sell products—claim that there are predictably different effects from red vein kratom varieties from Bali compared with green and white kratom varieties from Malaysia.

Differences in color and geographic origin lead people to wonder if different varieties of kratom might have different relative proportions of alkaloids in them. There are theories about the age of the tree at harvest, for example.

However, there is not yet enough research to support this, and the kratom industry itself is poorly regulated. Most online strain names are arbitrary devices generated by marketers. In fact, you may actually be buying multiple batches from the same plant, despite different strain names if they come from the same disreputable vendor.

What are Kratom Vein Colors?

Yes, as kratom strains are not a fact-based thing, so something similar is true about kratom vein colors. Kratom veins do have colors, typically one of four: green, yellow, red, and white. However, vein colors in products do not actually correspond to kratom leaf vein color, and at times leaves with different vein colors appear on a single tree. Sun exposure and drying is what changes the color of kratom products.

So, why do users feel these kratom products make them feel different? This is principally because of chemical differences between batches. Any natural product will vary from batch to batch, and the alkaloid content of kratom products is no different, often varying significantly. A two gram serving of kratom may contain 10 to 30 milligrams of mitragynine, depending on the batch.

Final Thoughts on Kratom

Kratom is trending in a major way, and it’s not at all clear that prohibition will win out in this case, this time. In fact, with enough research even Big Pharm companies and larger biotech businesses may try to get in on kratom. Get the facts about this substance, though, before you try it—right here.