Alkaloid Encyclopedia
Plain-language profiles of the alkaloids found in kratom. Every claim is sourced from peer-reviewed literature. Click any compound for its full profile.
Mitragynine
MIT · C₂₃H₃₀N₂O₄ · 398.5 g/mol
The most abundant alkaloid in kratom. A partial mu-opioid agonist responsible for the plant's core analgesic and stimulant properties at different doses.
Paynantheine
PAY · C₂₃H₃₀N₂O₄ · 398.5 g/mol
The second-most abundant kratom alkaloid. A smooth muscle relaxant with limited opioid receptor activity.
Speciogynine
SPEC · C₂₃H₃₀N₂O₄ · 398.5 g/mol
A diastereomer of mitragynine found in moderate amounts. Acts as a smooth muscle relaxant.
Speciociliatine
SPECI · C₂₃H₃₀N₂O₄ · 398.5 g/mol
Typically the third most abundant kratom alkaloid. Acts as an antagonist at mu-opioid receptors.
7-Hydroxymitragynine
7-OH · C₂₃H₃₀N₂O₅ · 414.5 g/mol
A potent mu-opioid agonist present in trace amounts. Despite low concentration it contributes significantly to kratom's analgesic effects.
Corynoxeine
CORYN · C₂₂H₂₆N₂O₄ · 386.46 g/mol
A minor oxindole alkaloid that inhibits acetylcholinesterase, a mechanism similar to some Alzheimer's medications.
Research & Synthetic Compounds
These compounds appear in kratom research literature but are not typically found in consumer products at meaningful levels, or are synthetic analogs used in pharmacological research.
Mitragynine Pseudoindoxyl
MPI · C₂₃H₂₈N₂O₅ · 412.48 g/mol
A rearrangement product of 7-hydroxymitragynine. A potent MOR agonist that does not recruit beta-arrestin-2 at analgesic doses.
View profileMGM-15
MGM-15 · C₂₄H₃₂N₂O₅ · 428.53 g/mol
A synthetic analog of mitragynine engineered for maximal G-protein bias.
View profileMGM-16
MGM-16 · C₂₄H₃₂N₂O₅ · 428.53 g/mol
A structural isomer of MGM-15 with enhanced metabolic stability.
View profileSR-17018
SR-17018 · C₂₁H₂₂FN₃O₃ · 383.42 g/mol
A non-indole MOR agonist structurally distinct from mitragynine-class compounds.
View profileMore alkaloid profiles are being added as peer-reviewed research is published.
Each profile undergoes source verification before publication.