Why noribogaine's long half-life complicates dosing protocols
Ibogaine's primary metabolite, noribogaine, persists in plasma for days after a single dose, raising questions about cumulative cardiac exposure that current monitoring protocols may not fully capture.
Ibogaine is metabolized in the liver primarily by CYP2D6 into noribogaine, a metabolite that pharmacokinetic studies suggest may persist in plasma for 24 to 72 hours after a single oral dose — and in some genetically slow metabolizers, considerably longer.
This persistence matters because noribogaine is independently active at several of the same receptor sites as the parent compound, and because its clearance overlaps with the window during which QT-interval prolongation has been observed clinically.
Current screening protocols at the more rigorous international clinics typically include CYP2D6 genotyping, but interpretation of results varies, and there is no consensus on how to adjust dosing for intermediate metabolizers. Researchers have called for standardized pharmacokinetic monitoring as a precondition for any expansion of clinical trials.