Speciociliatine
SPECI · CAS 570-44-5
Formula
C₂₃H₃₀N₂O₄
Molecular Weight
398.5 g/mol
Abundance in Leaf
3–10%
Last Reviewed
2026-03-12
What Is Speciociliatine?
Speciociliatine is typically the third most abundant alkaloid in kratom, making up roughly 3–10% of total alkaloid content. Unlike mitragynine, speciociliatine acts as an antagonist at mu-opioid receptors — meaning it partially blocks rather than activates them. This may help moderate the opioid-like effects of other alkaloids in the plant, contributing to kratom's overall effect profile being milder than classical opioids. It also shows activity at kappa-opioid receptors, which are associated with sedation and analgesia. Research into speciociliatine is still early-stage, and its full pharmacological role in kratom is not yet established.
Dose-Dependent Effects
Receptor Activity
Safety & Adverse Effects
Research status
Speciociliatine is an early-stage research compound. Limited human pharmacokinetic data is available. Its antagonist activity at MOR may reduce the opioid-like ceiling of whole-leaf kratom compared to purified mitragynine.
Source: Kruegel et al. 2018; Chear et al. 2021
Drug Interactions
CNS depressants (benzodiazepines, alcohol, opioids)
majorAs a component of whole-leaf kratom, speciociliatine is consumed alongside other alkaloids. Standard kratom interaction warnings apply.
COA Connection
Appears on Certificates of Analysis as: SPECI. Graded under Alkaloid Profile (Minor component).
View graded productsCited Literature
Kruegel AC, Grundmann O (2018). The medicinal chemistry and neuropharmacology of kratom: A preliminary discussion of a promising medicinal plant and analysis of its potential for abuse. ACS Chem Neurosci.
DOI: 10.1021/acschemneuro.7b00579Chear NJY, León F, Sharma A, et al. (2021). Exploring the chemistry of alkaloids from Malaysian Mitragyna speciosa (Kratom) and the role of oxindoles on human opioid receptors. J Nat Prod.
DOI: 10.1021/acs.jnatprod.0c01055