Ibogaine

What ibogaine is and how it works

Ibogaine is an indole alkaloid from the root bark of Tabernanthe iboga, a shrub from western Central Africa. There it is used in Bwiti rituals; outside Africa, mainly in treatments for addiction. Unlike psilocybin or ketamine, it usually involves a single, long session, after which withdrawal is supposed to subside and craving to diminish.

Ibogaine acts on several neurotransmitter systems at the same time. In the liver it is broken down via the enzyme CYP2D6 to noribogaine, which is also active and remains in the blood for a long time. How much ibogaine reaches the blood depends heavily on this enzyme: in a Dutch study, clearance rose by 30.7 liters per hour per CYP2D6 activity point. QT prolongation and unsteady gait were related there to the ibogaine level, not to noribogaine. Which part of the effect dampens withdrawal and which carries the lasting effects has not been established in humans.

The Stanford group gives ibogaine together with magnesium, because magnesium is supposed to lower the rhythm risk. This is a reasoned assumption by the authors, not the result of a comparison with and without magnesium.

What the studies show

Brown and Alper 2018: opioid withdrawal and one year of follow-up

30 people with opioid dependence, 25 men and 5 women, who on average had already been through 3.1 unsuccessful treatments; most took oxycodone, heroin or both. The withdrawal score fell from 31.0 to 14.0 points, measured about 76 hours after treatment. One month later, 15 of the 30 had taken no opioids in the previous 30 days. The drug use score was below baseline at all time points up to 12 months, most clearly after one month. There was no control group.

Noller 2018: ibogaine on prescription in New Zealand

In New Zealand, ibogaine is available on medical prescription. The study followed 14 people with opioid dependence, half women and half men, for 12 months after a single treatment. In the 8 who completed all interviews, the drug use score and depression scores were significantly lower after one year. One participant died during treatment.

Stanford 2024: magnesium-ibogaine in veterans with brain injury

The study in Nature Medicine followed 30 male special forces veterans with predominantly mild brain injury, treated with ibogaine plus magnesium and accompanying support. The primary endpoint, everyday functioning according to the WHO questionnaire, improved directly after treatment (d = 0.74) and after one month (d = 2.20). After one month, PTSD (d = 2.54), depression (d = 2.80) and anxiety (d = 2.13) also fell markedly. No unexpected or serious side effects occurred. The authors themselves write that controlled studies must follow.

Knuijver 2022: cardiac monitoring in a Dutch university hospital

14 people in opioid substitution with a persistent wish for abstinence received a single dose under monitoring for at least 24 hours. The QT interval lengthened by 95 milliseconds on average (29 to 146), half were temporarily above 500 milliseconds, and in 6 the prolongation lasted more than 24 hours. No dangerous arrhythmia occurred. All temporarily had such severe unsteady gait that they could only walk with assistance. 11 of 14 did not return to morphine within 24 hours.

What users report

An interview study from New Zealand questioned 10 people who had used ibogaine for opioid withdrawal. They associated the treatment with rapid withdrawal, better mood, less anxiety and phases of sustained abstinence; some later relapsed. They described preparation, a medical pre-examination and support afterwards as decisive (Walker 2026). These are experience reports, not proof of efficacy.

Where the data stop

• No control group. All efficacy data come from open-label studies. Whether part of the improvement is due to expectation, support or the natural course cannot be separated in this way.
• Small groups and dropouts. 30, 14 and 30 participants; in New Zealand, complete data after 12 months were available for only 8.
• Weak evidence overall. A 2025 systematic review of psychedelics in opioid dependence found mostly weak designs with a high risk of bias and hardly any blinded studies.
• Veterans study not transferable. Only men, a special group, and ibogaine was combined with further support. The study says nothing about opioid dependence.
• Magnesium as protection is untested. Whether the combination actually lowers the cardiac risk has not been investigated in a comparison.

Status, approval and legal

In Germany, ibogaine is listed neither in the schedules of the Narcotics Act (BtMG) nor in Annex 1 of the Ordinance on Prescription-Only Medicines (query 07.10.2026). There is no approved ibogaine medicine either in Germany or in the EU. In the US, ibogaine is a Schedule I controlled substance and not approved by the FDA. In New Zealand it is available on medical prescription.

In 2025, Texas passed the law SB 2308. It regulates a consortium of at least one pharmaceutical company, one university and one hospital that is to conduct FDA approval trials for opioid dependence, co-occurring substance use disorders and other neurological or psychiatric conditions. State funds flow only if matching funds from non-state sources are added.

Safety

The most important risk concerns the heart. Ibogaine prolongs the QT interval, that is, the phase in which the heart chambers recover electrically; if it is greatly prolonged, the risk of dangerous arrhythmias rises. In the monitored study, half of the patients were temporarily above 500 milliseconds, and in 6 of 14 the prolongation lasted longer than one day. An analysis of all known deaths outside western Central Africa from 1990 to 2008 counted 19 people who died within 1.5 to 76 hours after intake; in 12 of 14 well-documented cases, pre-existing heart conditions or other drugs contributed. As further risk factors, the analysis names seizures during simultaneous withdrawal from alcohol or benzodiazepines and untested plant preparations.

On top of this come severe, temporary unsteady gait and a metabolism that varies greatly from person to person. The authors of the Dutch study recommend testing lower amounts or amounts adjusted to CYP2D6 type. This text is information and does not replace medical advice.

Sources

• Cherian KN et al., Nature Medicine 2024 – magnesium-ibogaine in 30 veterans with brain injury (Stanford, MISTIC)
• Brown TK, Alper K, Am J Drug Alcohol Abuse 2018 – ibogaine in opioid dependence, withdrawal and use over 12 months, 30 participants
• Noller GE et al., Am J Drug Alcohol Abuse 2018 – ibogaine in opioid dependence in New Zealand, 12-month observation, 14 participants
• Knuijver T et al., Addiction 2022 – safety of ibogaine in opioid withdrawal: QT interval, unsteady gait, 14 patients
• Knuijver T et al., J Psychopharmacol 2024 – pharmacokinetics of ibogaine and noribogaine, influence of CYP2D6
• Alper KR et al., J Forensic Sci 2012 – 19 deaths temporally associated with ibogaine, 1990 to 2008
• Weleff J et al., Psychiatry Res 2025 – systematic review of psychedelics in opioid dependence
• Walker J et al., J Psychoactive Drugs 2026 – interviews with 10 users of ibogaine for opioid withdrawal in New Zealand
• Texas Senate Research Center, analysis of SB 2308 (enrolled version, 2025) – ibogaine consortium for FDA approval trials, ibogaine Schedule I in the US
• German Narcotics Act (BtMG), Annex I (ibogaine not listed, query 07.10.2026)