Substance info: Kratom

Kratom (Mitragyna speciosa) is a tropical tree growing from 15-50 feet tall (5-15 meters) that is native to Thailand and Malaysia. It has broad, oval leaves that taper to points, yellow flowers that grow in clusters, and winged seeds. The primary active chemicals are mitragynine, mitraphylline, and 7-hydroxymitragynine, all found in the leaves. Kratom leaves have been chewed for stimulant, sedative, and euphoric effects by people in Thailand and South Asia for centuries. They can also be smoked, brewed as a tea, or made into an extract. Kratom use is relatively uncommon in the US and Europe, though it is available in raw and extract-enhanced forms from ethnobotanical vendors.

Dose

Kratom leaves differ greatly in potency, depending on the type, grade, and freshness. Leaves with green veins are often claimed to be more potent than those with red veins, but there is contradictory evidence. Low doses are around 2-4 g of plain dried leaf, moderate doses are 3-6 g, and strong doses are 5 g or more. When chewed fresh, half of a large leaf (8-10") is often enough to produce noticeable effects.

Price

Dried, untreated leaves are available from ethnobotanical vendors for 30-80 cents (USD)/gram. Higher potency extracts may cost $2-8 USD/gram. (2009 data)

Law

Kratom is currently uncontrolled in the United States and many other countries. In 1946 it was made illegal to buy, sell, or grow in Thailand, and in 2005, both M. speciosa and mitragynine were made illegal to buy, sell or possess without a license in Australia.

Chemistry

Kratom leaves contain the indole alkaloids mitragynine, mitraphylline, 7-hydroxymitragynine, and numerous other alkaloids, including paynanthine, speciogynine, and speciofoline. Mitragynine has traditionally been cited as the primary active chemical in kratom leaves, but some recent evidence points to 7-hydroxymitragynine instead.

Pharmacology

Mitragynine is a partial agonist of the mu- and delta-opioid receptors. This may account for its apparent efficacy in treating opiate withdrawal. Because kratom acts as both a stimulant and a sedative, secondary alkaloids may be pharmacologically important.

Production

Kratom grows wild in marshy regions in Asia and the Pacific Rim, especially Thailand, Malaysia, Borneo, and New Guinea.

History

Kratom appears to have been used in Thailand for centuries, recreationally and as an antidiarrhetic. Its use as an opiate substitute in Malaysia was reported in the nineteenth century. Peasants have used it to counteract the tedium of physical labor, similar to the use of coca in South America. The chemistry of its alkaloids was investigated in the 1920s, and mitragynine was isolated in 1923. Kratom leaves became part of the ethnobotanical trade in the United States and Europe in mid 2000. In the early 2000s, stories about the use of kratom to reduce opiod withdrawal effects began circulating on web forums.

Effects

Kratom is often described as producing simultaneous, contradictory effects. Users report both an opiate-like sedation and coca-like stimulation. The stimulating effects tend to predominate at low dose levels, which may cause alertness, energy, and mild euphoria. Higher doses tend to be more tranquilizing, causing an opiate-like dreamy reverie. Excessive doses can cause severe nausea. Kratom is sometimes used as an opium substitute and has been found to suppress symptoms of opiate withdrawal. As with opium, it is known for causing constipation, and is sometimes used as a treatment for diarrhea.

Onset

When taken orally, kratom effects typically become noticeable in 15-20 minutes and clearly apparent in 30-60 minutes. Strong doses may have a more rapid and dramatic onset.

Duration

A moderate kratom dose can cause strong effects lasting 2-4 hours, though residual effects can last hours longer. Users sometimes experience an afterglow the next day.

Positive effects

Simultaneous stimulation & sedation
Feelings of empathy and euphoria
Aphrodisiac qualities for some people
Vivid waking dreams
Useful with physical labor

Visual effects

Some visual effects are reported, including both open-eye and closed-eye effects, though they are considered fairly mild if they occur at all. Effects reported include wavering, shifting, and strobing in the visual field; some patterning with eyes closed; and increased closed-eye visualizations.

Risks

Kratom is not known to be toxic, but it can be quite unpleasant at high doses, causing nausea and vomiting. Regular use can lead to physical dependency. Kratom use can cause constipation similar to that caused by opiates. Chronic heavy use is reported to cause darkening of skin, insomnia, dry mouth, and anorexia.

Contraindications

Do not operate heavy machinery. Do not drive. Care should be taken if combining with other sedatives (or stimulants). Use extreme caution if combining with MAO inhibitors. Kratom could be dangerous to combine with an MAOI.

Addiction potential

There are reports of physical dependency after frequent, heavy kratom use. Individuals who use it regularly or in large doses may find it difficult to stop. Withdrawal symptoms include irritability, yawning, diarrhea, runny nose, and pain in the joints or muscles.

Risks of death

We are not aware of any cases of severe poisoning or death resulting from its use. Animal studies have found even very large doses of mitragynine (920 mg/kg) to be non-lethal.