Medically reviewed by Dr. Irvine Russell, M.D. (UC Irvine)
Kratom (Mitragyna speciosa) is a tropical tree in the coffee family (Rubiaceae), native to Southeast Asia. Its dried leaves contain mitragynine and 7-hydroxymitragynine (7-OH) — alkaloids that bind mu-opioid receptors as partial agonists. Low-dose effects resemble mild stimulation; higher doses resemble opioid-like sedation and analgesia. Traditional use dates back centuries in Thailand, Malaysia, and Indonesia. Kratom is federally legal in the US but banned in six states. Regular use produces physical dependence and withdrawal on cessation.
Mitragyna speciosa — Rubiaceae family, same as coffee
Mitragynine (~1.5-2%) + 7-hydroxymitragynine (<0.02%). >40 total alkaloids.
Mu-opioid partial agonist. Also alpha-2 adrenergic, 5-HT2A/2C, GABA-A modulation.
Native to Thailand, Malaysia, Indonesia, Borneo. Traditionally chewed or brewed as tea.
Raw powder or capsules. Mitragynine-dominant. Mildest dependence risk. Slower onset (30-60 min). What most new users should start with.
OPMS Gold, MIT 45. Concentrated mitragynine. Faster onset, stronger effects, higher dependence risk. Treat with care.
Hydroxie, 7 OHMZ, 7 Tabz. Selectively concentrated 7-hydroxymitragynine. Highest potency and highest abuse liability. FDA scheduling watch.
At low doses (1-5g leaf), kratom produces mild stimulation, sociability, and energy. At higher doses (5-10g+ leaf), effects shift toward sedation, analgesia, and euphoria — more opioid-like. Extract products and 7-OH tablets produce stronger effects at lower doses. Mechanism is primarily mu-opioid receptor partial agonism, but kratom also acts on alpha-2 adrenergic, serotonergic, and GABAergic systems.
Kratom is a partial mu-opioid agonist — unlike morphine or oxycodone (full agonists). It recruits beta-arrestin-2 less strongly, which likely explains its lower respiratory-depression risk. But partial agonism is not zero agonism: regular daily use produces downregulation, tolerance, and physical dependence. 7-OH binds with higher affinity than mitragynine, narrowing the gap to traditional opioids.
Kratom is federally legal in the United States. Six states ban it: Alabama, Arkansas, Indiana, Rhode Island, Vermont, Wisconsin. Several cities (San Diego, Sarasota, Jerseyville IL) have local restrictions. Age restrictions (21+) apply in multiple legal states. Internationally, kratom is banned in Thailand (historically, now legalized), Malaysia (originally), Australia, and several European countries.
Leaf kratom effects peak at 1-2 hours and last 3-5 hours total. Extract shots kick in faster (15-30 min) and may last 4-6 hours at higher doses. 7-OH tablets peak faster and produce shorter but more intense effects, followed by a more pronounced comedown.
Yes. Physical dependence develops with daily use over several weeks; psychological dependence can develop faster. Heavy daily users (multiple times per day, extracts, or 7-OH products) are at meaningfully elevated dependence risk versus light leaf users. Regular users should plan tolerance breaks.
Opioid-like in character, milder than traditional-opioid withdrawal in most cases but still uncomfortable. Symptoms: insomnia, restless legs, anxiety, runny nose, muscle aches, irritability, GI upset, cravings. Typical duration 3-7 days for mild-moderate dependence; longer for heavy daily extract/7-OH users. Medical taper is the safer approach for heavy users.
Do not use kratom during pregnancy — neonatal abstinence syndrome has been documented. Kratom interacts dangerously with benzodiazepines, alcohol, opioids, and sedative antihistamines (additive respiratory depression). CYP3A4 and CYP2D6 inhibition means it can affect levels of many common prescriptions. Consult a pharmacist before combining with any prescribed medication.
AKA-GMP = American Kratom Association Good Manufacturing Practices. It's a self-regulatory certification requiring brands to follow FDA food-manufacturing standards, provide third-party lab testing (Certificates of Analysis) for mitragynine content, 7-OH content, heavy metals, microbial contamination, and solvents. It's the baseline quality signal in US kratom retail. Brands with AKA-GMP: Club 13, Super Speciosa, Earth Kratom, Whole Herbs.
