Nature communications
September 20, 2024
Václav Havel, Andrew C Kruegel, Benjamin Bechand et al.
18 citations
A new class of iboga alkaloids, called oxa-iboga, was created by modifying the iboga molecular structure to replace a key component with a benzofuran ring. These compounds lack the heart rhythm risks (proarrhythmic effects) of ibogaine and noribogaine when tested on human heart cells. In male rats, oxa-iboga compounds were more effective than ibogaine at reducing opioid use. They act as potent kappa opioid receptor agonists but produce different behavioral effects than typical kappa agonists. A single dose or short treatment with oxa-noribogaine led to long-lasting reductions in morphine, heroin, and fentanyl intake, reversed persistent opioid-induced pain sensitivity, and suppressed drug-seeking behavior in relapse models. These compounds offer a mechanistically distinct approach to treating opioid use disorder.
bioRxiv (Cold Spring Harbor Laboratory)
July 23, 2021
Václav Havel, Andrew C. Kruegel, Benjamin Bechand et al.
3 citations
preprint
A new class of iboga alkaloids, called oxa-iboga, was created by modifying the iboga skeleton to include a benzofuran group. These compounds act as potent kappa opioid receptor agonists but show atypical behavioral effects compared to standard kappa psychedelics. Oxa-noribogaine, a key oxa-iboga compound, demonstrated greater therapeutic efficacy in rat models of opioid use than noribogaine, with no cardiac pro-arrhythmic potential. A single dose produced long-lasting suppression of morphine and fentanyl intake, and a short treatment regimen persistently reduced morphine intake and reinforcing efficacy. It also suppressed drug seeking in relapse models and elevated neurotrophin proteins in brain regions linked to addiction, suggesting targeted neuroplasticity. Oxa-iboga compounds are candidates for a novel pharmacotherapy for opioid use disorder.
Journal of the American Chemical Society
December 26, 2025
Christopher Hwu, Václav Havel, Xavier Westergaard et al.
2 citations
Ibogaine and its main metabolite noribogaine inhibit the vesicular monoamine transporter 2 (VMAT2) with submicromolar potency, as shown in cell-based assays and two-photon microscopy of mouse brain synaptic vesicle clusters. Noribogaine also induces partial serotonin release from synaptic vesicles and binds VMAT2 at a distinct site from the established inhibitor dihydrotetrabenazine. These compounds additionally inhibit plasma membrane monoamine transporters, prominently the serotonin transporter (SERT), and a novel target, organic cation transporter 2 (OCT2). Several iboga analogs display dual inhibition of VMAT2 and SERT with comparable potencies, termed "Synaptic Reuptake Inhibitors" (SynRIs). This profile explains why ibogaine and noribogaine do not induce catalepsy, unlike other VMAT2 inhibitors, and illustrates the complex "matrix pharmacology" of iboga compounds.
ChemRxiv
March 19, 2020
Paola Rodrı́guez, Jessika Urbanavicius, José Pedro Prieto et al.
1 citation
Ibogaine and its main metabolite noribogaine produce antidepressant-like effects in rats in a dose- and time-dependent manner, without altering locomotor activity. Noribogaine's effect is short-lived (30 minutes) and correlates with high brain concentrations (estimated > 8 µM free drug), while ibogaine's effect is significant at 3 hours. At that time, both compounds are present in the brain at concentrations (ibogaine ~0.5 µM, noribogaine ~2.4 µM) that alone cannot produce the same behavioral outcome, suggesting a polypharmacological mechanism underlies their antidepressant-like effects.
Research Square
March 31, 2026
Marcus W. Meinhardt, Ivan Skorodumov, Florian Walter et al.
A compound derived from ibogaine, oxa-noribogaine, reduces alcohol consumption in rats by strengthening learning from negative drinking outcomes. It produces sustained decreases in alcohol intake and relapse-like drinking, matching or exceeding ibogaine's efficacy without detectable motor or cardiac side effects. These effects involve transient changes in prefrontal brain activity, lasting alterations in glutamatergic signaling after aversion-related learning, and normalization of neurotrophic signaling in cortico-striatal circuits. The results generalize across multiple models, genetically diverse animals, and independent study sites, identifying oxa-noribogaine as a promising treatment candidate for alcohol use disorder.