Ibogaine
12-methoxyibogamine
Overview
Ibogaine belongs to Psychedelics.
Effects
- A biphasic experience: an acute 'visionary' or oneirophrenic phase (dream-like, panoramic and often autobiographical visual imagery), followed by a long introspective/evaluative phase.
- Prominent physical effects: severe nausea and vomiting, marked ataxia and impaired coordination, tremor, and a slowed heart rate.
- A prolonged residual-stimulation phase (24–72 hours or more) with insomnia. A subsequent low-mood 'grey day' is well recognised and can, in some people, progress to a lasting depressive episode or mania.
- Qualitatively distinct from serotonergic psychedelics and closer to the harmala alkaloids. It does not dilate the pupils or raise blood pressure the way LSD does.
Dosing & duration
Oral. Ibogaine must never be taken without prior cardiac screening (ECG/QTc) and continuous cardiac monitoring: the doses used are large, the drug and its long-lived metabolite block hERG channels, and unsupervised use has caused fatal arrhythmias. Effects and blood levels also depend strongly on CYP2D6 metabolizer status, so a given dose is far less predictable between individuals than the numbers below suggest.
Dose ranges
8–50 mg
200–400 mg
≈1,000–1,500 mg (roughly 10–20 mg/kg)
Duration
1–3 h
≈2 h
Acute effects 18–36 h, residual stimulation and insomnia 24–72 h or longer
Chemical & Physical Properties
| Formula | C20H26N2O |
| Molar mass | 310.43 g/mol |
| State | Not reported |
| Melting point | 148–153 °C (free base, reported values vary) |
| Boiling point | Not reported |
| Density | Not reported |
| Vapor pressure | Not reported |
| pKa | Not reported |
| LogP | 3.9 (predicted, XLogP3) |
| Solubility | Soluble in chloroform |
| Refractive index | Not reported |
Identifiers & Synonyms
| CAS | 83-74-9 |
| CAS (enantiomer) | |
| PubChem CID | 197060 |
| InChIKey | HSIBGVUMFOSJPD-CFDPKNGZSA-N |
| InChI | InChI=1S/C20H26N2O/c1-3-13-8-12-9-17-19-15(6-7-22(11-12)20(13)17)16-10-14(23-2)4-5-18(16)21-19/h4-5,10,12-13,17,20-21H,3,6-9,11H2,1-2H3/t12-,13+,17+,20+/m1/s1 |
| SMILES | CC[C@H]1C[C@@H]2C[C@@H]3[C@H]1N(C2)CCC4=C3NC5=C4C=C(C=C5)OC |
Synonyms
- Ibogaine
- Tabernanthe iboga alkaloid
- Iboga
Pharmacodynamics & Biochemistry
Ibogaine has an unusually promiscuous, low-affinity pharmacology: rather than acting potently at a single receptor it binds many targets in the high-nanomolar to micromolar range. Its highest affinity is at the sigma-2 (σ2) receptor (Kᵢ ≈ 90–400 nM). It also interacts with the NMDA-receptor PCP/MK-801 site, κ- and μ-opioid, α3β4 nicotinic acetylcholine and sigma-1 receptors, and inhibits the serotonin and dopamine transporters and VMAT2. Unlike classic serotonergic psychedelics, ibogaine is only a weak ligand of 5-HT2A and does not act as a direct 5-HT2A agonist (it fails to produce the rodent head-twitch response). Its distinctive dream-like, oneirogenic effects are qualitatively closer to the harmala alkaloids than to LSD or psilocybin. Animal drug-discrimination work implicates 5-HT2A/2C, σ2 and opioid signalling, but not the NMDA, 5-HT1A or 5-HT3 receptors, in its subjective effects. Antagonism of α3β4 nicotinic acetylcholine receptors is a leading candidate mechanism for its reported anti-addictive effects, and is the property carried forward into synthetic analogues such as 18-MC. Much of ibogaine's activity is mediated by its major active metabolite noribogaine (12-hydroxyibogamine), formed by CYP2D6 O-demethylation. Noribogaine is a more potent serotonin-reuptake inhibitor (Kᵢ ≈ 41 nM) and a G-protein-biased κ-opioid receptor agonist (Kᵢ ≈ 0.7 µM). Unlike ibogaine it does not bind σ2, and it has a much longer half-life and reaches higher plasma levels than the parent drug. Block of the hERG (Kᵥ11.1) cardiac potassium channel (Kᵢ ≈ 710 nM) underlies ibogaine's most dangerous effect: prolongation of the QT interval with a risk of torsades de pointes and fatal arrhythmia.
Biological targets
- Sigma-2
- SERT
- hERG
- NMDA
- nAChR
- DAT
- KOR
- MOR
- Sigma-1
- 5-HT2A
Binding & functional measurements
| Target | Measurement | Species |
|---|---|---|
| σ2 receptor | Ki 200 nM | Rat/guinea pig/calf |
| SERT | Ki 549 nM | Human |
| hERG | Ki 710 nM | Human |
| NMDA | Ki 1,010 nM | Rat/bovine/human |
| nAChR | Ki 1,050 nM | Human |
| DAT | Ki 1,980 nM | Human |
| σ1 receptor | Ki 2,500 nM | Guinea pig/calf |
| KOR | Ki 3,700 nM | Human |
| MOR | Ki 6,920 nM | Human |
Pharmacokinetics
| Bioavailability | Oral, variable and influenced by CYP2D6 metabolizer status |
| Tmax | ≈2 h |
| Half-life | Ibogaine ≈ 7 h, active metabolite noribogaine ≈ 24–50 h |
| Vd | Not reported |
| Protein binding | Not reported |
| Metabolism | Hepatic CYP2D6 O-demethylation to the active metabolite noribogaine (12-hydroxyibogamine). Ibogaine is also deposited in fat and released slowly |
| Excretion | Renal and biliary |
Toxicology & Safety
Not reported
Ibogaine's defining hazard is cardiotoxicity: by blocking the hERG (Kᵥ11.1) potassium channel it prolongs the QT interval and can trigger torsades de pointes and fatal cardiac arrest: sometimes hours after dosing and during the long noribogaine tail. Multiple deaths have been documented in case series and reviews, typically in unsupervised or medically unscreened settings and frequently involving pre-existing heart disease or co-used opioids or other QT-prolonging drugs. It should only ever be considered with prior cardiac screening, continuous ECG monitoring and emergency care available. Acute effects also include severe ataxia, tremor and protracted nausea/vomiting, and afterwards a low-mood 'grey day' that can develop into a lasting depression or, less often, mania. High doses cause Purkinje-cell degeneration in the rat cerebellum. This has not been confirmed in primates or humans, but human safety is not established. Limited or absent controlled-trial data must never be read as evidence of safety.[13][14][16][18][19]
Legal Status
US: Schedule I. UK: Controlled (PSA 2016). DE: Not scheduled (BtMG)
Interactions & Contraindications
Drug interactions
Contraindications
No interactions or contraindications listed.
Usage & Context
- Investigational treatment for opioid and other substance-use disorders (interruption of withdrawal and craving). Only two randomized controlled trials exist and efficacy and safety remain unconfirmed.
- Traditional sacramental and initiatory use of Tabernanthe iboga root bark by the Bwiti of Gabon and neighbouring Central African peoples.
- Used at 'legal gray area' clinics abroad (e.g. Mexico, Costa Rica, the Netherlands, New Zealand, South Africa), while remaining federally illegal in the United States.
Sources & Evidence
- PubChem: Ibogaine (CID 197060) — identifiers & properties
- Wikipedia: Ibogaine (pharmacology table, dosing, phases & legal status) CC BY-SA 4.0
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