Mitragynine Pseudoindoxyl

The following information was compiled in November 2025 and is subject to change as new research is conducted and as new information becomes available:

Description: Mitragynine pseudoindoxyl is categorized as a semi-synthetic analogue of mitragynine, the primary psychoactive component in Mitragyna speciosa (Kratom). Mitragynine pseudoindoxyl is also a metabolite of mitragynine through 7-hydroxymitragynine and rearrangement of the hydroxyl-imine to a spiropseudoindoxyl core.^1,2 Mitragynine pseudoindoxyl has emerged as a primary component in drug products, often found alongside 7-hydroxy mitragynine and marketed as “Kratom” or alternatives.³ Mitragynine pseudoindoxyl was first identified by our laboratory in September 2025 and confirmed after acquiring standard reference material.

Sample Source: CFSRE NPS Discovery Test Purchase Program (Philadelphia, PA)

Sample Appearance: Pills and tablets

Pharmacology: Mitragynine pseudoindoxyl (MP) is reported to be a potent mu-opioid receptor agonist with higher potency and affinity compared to mitragynine (MG) and 7-hydroxy mitragynine (7-OH-MG)    [K_i (nM)= 1.5 (MP), 78 (7-OH-MG), 709 (MG); ED₅₀ (µmol/kg) = 0.47 (MP), 0.66 (7-OH-MG), 2.4 (MG)].^4,5

Toxicology: Mitragynine pseudoindoxyl has been detected in >10 toxicology cases to date at the CFSRE.

Drug Materials: Mitragynine pseudoindoxyl has been detected in >10 drug materials to date at the CFSRE.

Demographics / Geographics: The first drug materials originated from Pennsylvania and Illinois. Mitragynine pseudoindoxyl was identified alongside other kratom alkaloids.

Legal Status: Mitragynine pseudoindoxyl is not currently scheduled in the United States.

Class:

Miscellaneous

Appearance:

Pills and tablets

Formula:

C23H30N2O5

MW:

414.5

[M+]:

414

[M+H]+:

415.2227

IUPAC:

methyl (E)-2-(6-ethyl-4'-methoxy-3'-oxo-spiro[3,5,6,7,8,8a-hexahydro-2H-indolizine-1,2'-indoline]-7-yl)-3-methoxy-prop-2-enoate

Report Date:

November 7, 2025