Kratom
Mitragyna speciosa leaf with opioid partial-agonist alkaloids and a dose-dependent stimulant-to-sedative profile.
Pharmacology
Contents
WHAT IS KRATOM?
Detailed overview
Kratom is the dried leaf of the Southeast Asian tree Mitragyna speciosa, whose main active constituents are the alkaloids mitragynine and 7-hydroxymitragynine. These act as partial agonists at opioid receptors while also engaging serotonergic and dopaminergic pathways, giving a dose-dependent profile: stimulant-like and energizing in smaller amounts, opioid-like sedation and pain relief in larger ones. Traditionally chewed by laborers for fatigue and pain, modern use has shifted toward chronic pain management, mood support and self-treatment of opioid withdrawal. Human pharmacokinetic and observational data exist, but large controlled efficacy trials are lacking, and regular heavy use carries genuine dependence and withdrawal risk.
Mechanism
Mu-opioid partial agonist (mitragynine)
Onset
15-45 min, dose-dependent profile
Legal status
Varies by country; banned in several
Receptor profile
- Mu-opioid receptorStrong
- Delta- and kappa-opioid receptorsModerate
- Alpha-2 adrenergic receptorWeak
- Serotonin (5-HT) receptorsWeak
Safety
Side effects, stop signs, contraindications
Side effects · 6
- Nausea and vomiting, especially at higher doses or in new users
- Constipation and reduced appetite (opioidergic side effect)
- Dependence and tolerance with regular, heavy use
- Withdrawal symptoms on cessation (pain, sleep problems, irritability, cravings)
- Less commonly liver injury (cholestatic pattern), seizures and tachycardia
- Contamination risk: heavy metals (lead), Salmonella and inconsistent alkaloid content have been found in unregulated products
Contraindications · 5
- Pregnancy and breastfeeding: safety not established, avoid
- Concurrent opioids, benzodiazepines, alcohol or other CNS depressants: increased respiratory depression and fatality risk
- Pre-existing liver or heart disease, arrhythmia
- History of opioid dependence or addiction: risk of cross-dependence and relapse
- CYP2D6/CYP3A4-inhibiting drugs may raise mitragynine plasma levels
Related Nootropics
Same therapeutic category
Studies
Related research and clinical findings
Pharmacokinetics of mitragynine in man
Trakulsrichai S, Sathirakul K, Auparakkitanon S, Krongvorakul J, Sueajai J, Noumjad N
Severity of Pain and Sleep Problems during Kratom (Mitragyna speciosa Korth.) Cessation among Regular Kratom Users
Singh D, Narayanan S, Vicknasingam BK, Prozialeck WC, Ramanathan S, Zainal H
Kratom use in the United States: a diverse and complex profile
Grundmann O, Babin JK, Henningfield JE, Garcia-Romeu A, Kruegel AC, Prozialeck WC
Exploring the self-reported motivations of kratom (Mitragyna speciosa Korth.) use: a cross-sectional investigation
Grundmann O, Veltri CA, Morcos D, Knightes D 3rd, Smith KE, Singh D
In Vitro and In Vivo Pharmacokinetic Characterization of 7-Hydroxymitragynine, an Active Metabolite of Mitragynine, in Sprague-Dawley Rats
Chiang YH, Kanumuri SRR, Kuntz MA, Senetra AS, Berthold EC, Kamble SH
FAQ
FAQ
Mitragyna speciosa leaf with opioid partial-agonist alkaloids and a dose-dependent stimulant-to-sedative profile.
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Structure & chemistry
The information here is strictly for educational and scientific purposes. It does not replace medical advice or clinical consultation, and it does not encourage illegal substance or pharmaceutical use. Data is sourced. When in doubt, consult your doctor.