Mechanisms · Mechanism of Action
Noribogaine — The Long-Tail Metabolite
Noribogaine is ibogaine's CYP2D6-formed metabolite — cleaner mu-opioid partial-agonist profile, lower hERG signal, longer half-life. The molecule that drives the post-flood-dose tail.
Quick Answer
What is noribogaine — the long-tail metabolite in ibogaine pharmacology?
Reviewed by Dr. Arellano, M.D. — May 2026
Formation and disposition
Noribogaine is formed by CYP2D6-mediated O-demethylation of ibogaine, primarily in the liver. The conversion rate depends heavily on CYP2D6 metabolizer status (see the Pharmacokinetics deep-dive).
Once formed, noribogaine is highly lipophilic and accumulates in adipose tissue. Plasma elimination half-life estimates range from 28 to 49 hours, substantially longer than parent ibogaine.
Receptor profile differences from parent ibogaine
Compared to ibogaine, noribogaine has a cleaner pharmacological signature: stronger mu-opioid partial-agonist activity, kappa-opioid partial-agonist activity, serotonin transporter inhibition, and a notably smaller hERG/QT signal in cardiac assays.
These differences are why noribogaine has been explored as a stand-alone development candidate (Glue et al. 2015, 2016) — it preserves the long-tail anti-craving and mood-elevating effects while reducing the acute QT-prolongation risk that comes with parent ibogaine.
- Mu-opioid receptor: partial agonist (cleaner than parent ibogaine).
- Kappa-opioid receptor: partial agonist activity.
- Serotonin transporter (SERT): inhibition — contributes to mood-elevating tail.
- hERG channel: substantially smaller QT-prolongation signal.
Why telemetry extends 72-96 hours
Although parent ibogaine clears within 24-36 hours of the flood dose, noribogaine concentrations remain pharmacologically active for days. The MindScape cardiac telemetry window is calibrated to this metabolite tail — not to parent ibogaine elimination.
This is also why patients can describe sustained mood and anti-craving effects in the week after the flood dose: the noribogaine tail is doing the work.
Targets
- Mu-opioid receptor (partial agonist)
- Kappa-opioid receptor
- Serotonin transporter (SERT)
- hERG channel (low signal)
- CYP2D6 substrate
Citations & Reading
- Glue P, et al. (2015). Drug Metabolism and Disposition, 43(1), 119-125.
- Glue P, et al. (2016). Clinical Pharmacology in Drug Development, 5(6), 460-468.
- Mash DC, et al. (2018). Frontiers in Pharmacology, 9, 529.
- Maillet EL, et al. (2015). Neuropharmacology, 99, 675-688.
For broader clinical context, see the 2026 evidence-base review and the onsite taper cohort methodology page.
Related mechanisms
Ibogaine Pharmacokinetics
Absorption, CYP2D6 metabolism to noribogaine, distribution, and elimination — including the long noribogaine tail that drives the post-flood telemetry window.
Mu-Opioid Receptor
Ibogaine and noribogaine interact with the mu-opioid receptor at low affinity — but the clinical effect on opioid withdrawal is multifactorial, not a simple substitute-and-taper.
BDNF & GDNF Upregulation
Ibogaine and noribogaine upregulate brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF), driving downstream neuroplasticity and dopaminergic repair.