Ibogaine

Neurotoxicity

Laboratory studies in rats indicate that ibogaine at high doses may cause degeneration of Purkinje cells in the cerebellum.^{[28][24][29][30]} This also occurred with the related drug harmaline.^[29][30] However, subsequent research found no evidence of this neurotoxicity with ibogaine in a primate.^[31] In limited human research, neuropathological examination revealed no evidence of neuronal degenerative changes in an adult female patient who had received four separate doses of ibogaine ranging between 10 and 30 mg/kg over a 15-month interval.^[31] A published series of fatalities associated with ibogaine ingestion also found no evidence for consistent neurotoxicity.^[28][27]

Pharmacodynamics

Ibogaine affects many different neurotransmitter systems simultaneously and hence has complex pharmacology.^[53][14][2] The specific targets mediating the effects of ibogaine are not fully clear.^[54][2] The drug is a cyclized derivative of serotonin, and hence may be expected to have serotonergic actions, but shows relatively low affinity for serotonin receptors.^[53] In any case, it appears that the serotonin 5-HT_2A, 5-HT_2C, sigma σ₂, and μ- and/or κ-opioid receptors may be involved in the subjective effects of ibogaine based on animal studies.^[54][2] Conversely, the NMDA, serotonin 5-HT_1A and 5-HT₃, and sigma σ₁ receptors do not appear to be involved.^[54][2]

Ibogaine's major active metabolite noribogaine has similar discriminative stimulus properties compared to ibogaine in rodent drug discrimination tests, but only partially substitutes for ibogaine.^[54][2] It appears that the stimulus properties of ibogaine may be primarily mediated by noribogaine.^[54][2] Noribogaine is most potent as a serotonin reuptake inhibitor. It acts as a moderate κ-opioid receptor agonist^[43] and weak μ-opioid receptor agonist^[43] or weak partial agonist.^[42] The action of ibogaine at the κ-opioid receptor may indeed contribute significantly to the psychoactive effects attributed to ibogaine ingestion; Salvia divinorum, another plant recognized for its strong hallucinogenic properties, contains the chemical salvinorin A, which is a highly selective κ-opioid agonist. Noribogaine is more potent than ibogaine in rat drug discrimination assays when tested for the subjective effects of ibogaine.^[55]

There has been uncertainty about which biological target interactions mediate the psychoactive and other effects of ibogaine.^[53][54][2] Rodent drug discrimination studies with ibogaine have been employed to help elucidate these interactions.^[54][2] Ibogaine partially substitutes for the serotonergic psychedelics LSD and DOM and this can be blocked by the serotonin 5-HT₂ receptor antagonist pizotifen.^[54] Similarly, LSD and DOM partially substitute for ibogaine and this can be blocked by the serotonin 5-HT_2A receptor antagonist pirenperone.^[54][2][56] The serotonin releasing agent and potent serotonin 5-HT₂ receptor agonist fenfluramine also partially substitutes for ibogaine.^[54] The preferential serotonin 5-HT_2C receptor agonists MK-212 and mCPP partially substitute for ibogaine as well and this can be blocked by the serotonin 5-HT₂ receptor antagonist metergoline.^[54] The preceding findings suggest that serotonin 5-HT_2A and 5-HT_2C receptor activation are involved in the subjective effects of ibogaine.^[54][2] Conversely, the serotonin 5-HT_1A and 5-HT₃ receptors do not appear to be involved.^[54][2]

Although serotonin 5-HT_2A receptor signaling appears to be involved in the effects of ibogaine, neither ibogaine nor its major active metabolite noribogaine appears to act as a direct serotonin 5-HT_2A receptor agonist.^[40] In addition, in contrast to the findings in drug discrimination studies, ibogaine fails to produce the head-twitch response, a behavioral proxy of psychedelic effects, in rodents.^[53][57] As such, it has been said that ibogaine does not appear to be acting primarily or exclusively as a serotonergic psychedelic^[53][57] and that its hallucinogenic effects cannot be ascribed to serotonin 5-HT_2A receptor activation.^[6] In any case, ibogaine has still been found to have significant in-vivo occupancy of the serotonin 5-HT_2A receptor, suggesting that it is still a ligand of the receptor.^[54]

Ibogaine has been investigated as a potential treatment for substance use disorders, with proposed mechanisms including inhibition of α3β4 nicotinic acetylcholine receptors.^[45]

The β-carbolines or harmala alkaloids bear a close resemblance to ibogaine in terms of chemical structure and subjective effects.^[54] Relatedly, harmaline and 6-methoxyharmalan fully substitute for ibogaine in drug discrimination tests, whereas harmine, harmane, harmalol, and tryptoline partially substitute for ibogaine.^[54][2][58] As with the case of ibogaine, the psychedelic DOM partially substitutes for harmaline and this further supports a role of serotonin 5-HT_2A receptor activation in the effects of ibogaine as well as of harmala alkaloids.^[54] However, like ibogaine, harmala alkaloids like harmaline bound to the serotonin 5-HT_2A receptor but were inactive as direct agonists of the receptor even at very high concentrations in vitro.^[58][59][60] In addition, whereas ibogaine and noribogaine bind to κ-opioid receptors, harmala alkaloids like harmine and harmaline show no affinity for these receptors.^[61]

Ibogaine's hallucinogenic effects not being mediated by serotonin 5-HT_2A receptor activation has been said to be in accordance with its hallucinogenic effects in humans being qualitatively distinct from and unlike those of serotonergic psychedelics but instead similar to those of harmala alkaloids.^[57][62][63] It is also in accordance with the fact that unlike serotonergic psychedelics like LSD, neither ibogaine nor harmala alkaloids cause pupil dilation or increase blood pressure in humans.^[62] Conversely, unlike serotonergic psychedelics, ibogaine and harmaline are said to cause balance disturbances and vomiting to a greater extent than any other psychoactive drug besides alcohol.^[62]

Ibogaine shows appreciable affinity for the NMDA receptor.^[54] However, the NMDA receptor antagonists phencyclidine (PCP) and dizocilpine (MK-801) fail to substitute for ibogaine and ibogaine fails to substitute for these NMDA receptor antagonists in rodents and/or monkeys.^[54][2] Hence, NMDA receptor antagonism does not appear to be involved in the subjective effects of ibogaine.^[54][2] Neither μ-opioid receptor agonists nor κ-opioid receptor agonists like U-50,488 substitute for ibogaine.^[54] In addition, the opioid antagonist naloxone did not substitute for ibogaine.^[54] However, naltrexone partially substitutes for ibogaine.^[54] In addition, the mixed opioid agonists and antagonists pentazocine, diprenorphine, and nalorphine partially substituted for ibogaine and this could be antagonized by naloxone.^[54] The preceding findings suggest a role of opioid receptors but not the NMDA receptor in the effects of ibogaine.^[54][2]

The non-selective sigma receptor agonists DTG and (+)-3-PPP partially substitute for ibogaine, whereas the σ₁ receptor-selective agonists (+)-SKF-10,047 and (+)-pentazocine failed to substitute for ibogaine.^[54] These findings suggest a role of σ₂ receptor signaling in the effects of ibogaine.^[54]

Induction of gamma oscillations with a profile that resembles that of REM sleep may be involved in the hallucinogenic and oneirogenic effects of ibogaine.^[53][64]

Noribogaine, but not ibogaine, produces psychoplastogenic effects in vitro in preclinical research.^[65][53][66] This can be blocked by the serotonin 5-HT_2A receptor antagonist ketanserin, by the mTOR inhibitor rapamycin, and by a TrkB antagonist.^[65][66]

Pharmacokinetics

Ibogaine is metabolized in the human body by cytochrome P450 2D6 (CYP2D6) into noribogaine (more correctly, O-desmethylibogaine or 12-hydroxyibogamine). Both ibogaine and noribogaine have a plasma half-life around 2 hours in rats,^[67] although the half-life of noribogaine is slightly longer than that of the parent compound.^[6] In humans, the elimination half-life of ibogaine is about 7 hours whereas the half-life of noribogaine is 24 to 50 hours.^[6][7][8] Ibogaine may be deposited in fat and metabolized into noribogaine as it is released.^[68] After ibogaine ingestion in humans, noribogaine shows higher plasma levels than ibogaine and is detected for a longer period of time than ibogaine.^[69]

Synthesis

The chemical synthesis of ibogaine has been described.^[1]

One recent total synthesis^[70] of ibogaine and related drugs starts with 2-iodo-4-methoxyaniline which is reacted with triethyl((4-(triethylsilyl)but-3-yn-1-yl)oxy)silane using palladium acetate in DMF to form 2-(triethylsilyl)-3-(2-((triethylsilyl)oxy)ethyl)-1H-indole. This is converted using N-iodosuccinamide and then fluoride to form 2-(2-iodo-1H-indol-3-yl)ethanol. This is treated with iodine, triphenyl phosphine, and imidazole to form 2-iodo-3-(2-iodoethyl)-1H-indole. Then, using 7-ethyl-2-azabicyclo[2.2.2]oct-5-ene and cesium carbonate in acetonitrile, the ibogaine precursor 7-ethyl-2-(2-(2-iodo-1H-indol-3-yl)ethyl)-2-azabicyclo[2.2.2]oct-5-ene is obtained. Using palladium acetate in DMF, the ibogaine is obtained. If the exo ethyl group on the 2-azabicyclo[2.2.2]octane system in ibogaine is replaced with an endo ethyl, then epiibogaine is formed.

Crystalline ibogaine hydrochloride is typically produced by semisynthesis from voacangine in commercial laboratories.^[71][72] It can be prepared from voacangine through one-step demethoxycarbonylation process too.^[73]

In 2025, researchers at the University of California, Davis Institute for Psychedelics and Neurotherapeutics reported the total synthesis of ibogaine, ibogaine analogues, and related compounds from pyridine.^[74][75]

Analogues and derivatives

Analogues of ibogaine include noribogaine, ibogamine, ibogaline, tabernanthine, voacangine, coronaridine, oxa-noribogaine, and pinoline, among others.

A synthetic derivative of ibogaine, 18-methoxycoronaridine (18-MC), is a selective α3β4 antagonist that was developed collaboratively by neurologist Stanley D. Glick (Albany) and chemist Martin E. Kuehne (Vermont).^[76] This discovery was stimulated by earlier studies on other naturally occurring analogues of ibogaine, such as coronaridine and voacangine, that showed these compounds to have anti-addictive properties.^[77][78]

More recently, non- and less-hallucinogenic analogues, ibogalogs like tabernanthalog and ibogainalog, were engineered by scientists attempting to produce non-cardiotoxic ibogaine derivatives by removing the lipophilic isoquinuclidine ring. In animal models, both molecules failed to produce cardiac arrhythmias, and tabernanthalog failed to produce any head twitch response, suggesting psychedelic effects were absent.^[40][79] Other deconstructed analogues of ibogaine, such as 5-MeO-IsoqT, have also been developed and studied.^[80][40]

Legal status

As of 2024^[update], the legal status of ibogaine varies widely among countries, as it may be illegal to possess or use, may be legalized, may be decriminalized, or is under consideration for future legislation.^[102]

In the United States, although some cities and states have decriminalized psychedelic chemicals, plants and mushrooms, ibogaine has had minimal legislation, and remains illegal under federal law, as of 2026.^[102][103] The US Drug Enforcement Administration enforces ibogaine as a Schedule I substance under the Controlled Substances Act.^[20] A 2026 executive order in the US accelerates ibogaine research, regulatory review, patient access through Right to Try, and potential rescheduling if clinical trials and FDA approval criteria are successful.^[104] In March 2026, Texas announced plans to use $50 million approved by the Texas Legislature the previous year to create its own ibogaine research program after several proposals from drug companies failed to meet requirements for partnering with the state.^[105]

Treatment clinics

Ibogaine treatment clinics have emerged in Mexico, Bahamas, Canada, the Netherlands, South Africa, and New Zealand, all operating in what has been described as a "legal gray area".^[106][107] Costa Rica also has treatment centers.^[96] Covert, illegal neighborhood clinics are known to exist in the United States, despite active DEA surveillance.^[108] While clinical guidelines for ibogaine-assisted detoxification were released by the Global Ibogaine Therapy Alliance in 2015,^[109][110] addiction specialists warn that the treatment of drug dependence with ibogaine in non-medical settings, without expert supervision and unaccompanied by appropriate psychosocial care, can be dangerous — and, in approximately one case in 300, potentially fatal.^{[107][failed verification]}

Media

Psychotherapy

Ibogaine was used as an adjunct to psychotherapy by Claudio Naranjo, documented in his 1973 book The Healing Journey: New Approaches to Consciousness.^[62] He was awarded patent CA 939266 in 1974.^{[citation needed]}

Addiction treatment

A 2022 systematic review suggests that ibogaine and noribogaine show promise in treating substance use disorders and comorbid depressive symptoms and psychological trauma, but carry serious safety risks, necessitating rigorous clinical oversight.^[10] A 2023 review found that ibogaine and noribogaine show some potential in treating substance use disorders, especially opiate detoxification, but that their efficacy is unconfirmed and use carries significant cardiotoxic and mortality risks.^[11] A total of two randomized controlled trials have been conducted on ibogaine and noribogaine.^[10][11]

Texas research initiative

In 2025, the state of Texas allocated $50 million to fund clinical research on ibogaine, aiming to develop a U.S. Food and Drug Administration-approved treatment for opioid use disorder, co-occurring substance use disorders, and other ibogaine-responsive conditions.^[139][140] The initiative, supported by former Governor Rick Perry, established a consortium of universities, hospitals, and drug developers, with the goal of positioning Texas as a leading center for psychedelic medicine research.^[139]

Federal government initiative

A 2026 executive order directed US agencies to accelerate research, regulatory review, and potential patient access pathways for psychedelic drugs, including ibogaine, for serious mental illness.^{[141][142][12]}