Ibogaine Clinical Trials: What Has Actually Been Run

This page exists because the sentence people most often hear is that ibogaine is “in clinical trials”, and that sentence is doing a lot of work.

Trials have been registered. Some have finished. What has not happened is the part that would let anyone judge the drug.

The whole registry

Every interventional and observational ibogaine study registered on ClinicalTrials.gov, checked on 26 August 2026.

Three completed. Two withdrawn without enrolling a single person. No ibogaine study on this list has posted results to the registry.

Two entries on it are the same study. NCT07717866’s own description says so: “This project was formerly registered on clinicaltrials.gov (NCT06810765).” What changed between the two registrations is worth more than the count. The first was a phase 2 interventional study at Johns Hopkins. The second is an observational study run by an industry sponsor, registered in July 2026 with an actual start date of August 2022 and a primary completion date of February 2026. It was entered on the register nearly four years after enrolment began and five months after its primary endpoint was reached. Its enrolment field says 52; its own description says approximately forty took part.

NCT04313712 is also stale in a way the status does not convey. Its estimated completion was February 2025 and its last registry update was December 2024. It still reads active.

One has since reported in a journal. In July 2026 a pilot study of nine patients with moderate to severe alcohol use disorder was published, matching NCT03380728 in design, size, indication, institution and principal investigator. Five of the nine completed the protocol, five had QT interval changes, and two needed medication for agitation, insomnia and raised blood pressure. It declares no conflicts of interest.

That is the only trial on this list to have produced a public result, and its design changed on the way. The registry keeps every version, and the first one, filed in December 2017, describes a randomised study with single masking in which nine volunteers would receive ibogaine or placebo. The final entry describes a single group, no randomisation and no masking. The placebo arm was never run.

Its registered primary outcome, unchanged from first version to last, is time without using alcohol. The paper reports feasibility and safety. Ibogaine for alcoholism sets out what it does and does not establish.

The one trial that did post, and why you have not heard of it

The sentence above is exact, and the exactness is the point. No ibogaine study has posted results. A study of noribogaine, ibogaine’s principal metabolite, has, and it does not appear when you search the registry for ibogaine.

NCT06480981 was a randomised, triple-masked, placebo-controlled multiple-ascending-dose study of noribogaine in 55 healthy volunteers, run by DemeRx NB at Richmond Pharmacology in London. It completed in January 2025 and posted results on 22 January 2026. All 55 completed. There were no deaths, no serious adverse events and no discontinuations.

Then there is the adverse-event table.

Nothing on placebo. Seven of nine at the top dose. That is a clean dose-response for the cardiac signal, in healthy volunteers, in a trial the sponsor reported itself.

Two things about how it reached the public record matter. QT was never a registered outcome measure. The registered endpoints were pharmacokinetic: maximum concentration, time to it, area under the curve, half-life. The cardiac finding appears only in the adverse-event table, which trials are obliged to file whether or not anyone asked the question. And the study does not surface under the search term this page is about, so a reader auditing “ibogaine trials” will not find the one iboga-alkaloid trial that reported.

A second reported trial, on a register nobody checks

The registry table above is scoped to ClinicalTrials.gov, which is the convention and which is also how a completed, reported, published ibogaine trial goes missing.

EudraCT 2014-000354-11 was run by Radboud University Medical Centre in Nijmegen: an open-label, single-arm, single-fixed-dose study of ibogaine hydrochloride at 10 mg/kg in opioid-dependent patients. Fourteen were dosed out of 36 approached. It ended in October 2019, posted results on the EU register in May 2022, and was published as Knuijver et al. in Addiction in 2022.

Its registered primary endpoint was the difference between baseline QTc and the maximum QTc within 24 hours. The answer was a median of 102 milliseconds, and seven of the fourteen exceeded 500 milliseconds, in a cohort screened to exclude anyone already above 450 milliseconds for men or 470 for women. Every subject developed clinical cerebellar ataxia. There were no serious adverse events and no deaths.

It is an open-label safety study, so it does not disturb this page’s central claim that no randomised trial has published drug-use outcomes. It does disturb a weaker one: the alcohol pilot below is not the only ibogaine trial anywhere to have produced a public result. It is the only one on ClinicalTrials.gov.

The two that matter

Two of those studies were randomised and blinded, which is the design that can distinguish a drug effect from everything else that happens when a desperate person travels abroad, pays a great deal of money and is looked after for a week.

The larger, run by a pharmaceutical sponsor, enrolled 116 people across two stages, the second of which was randomised and double-blind. Its primary completion date was 16 January 2024. Its registry entry was last updated in August 2024 and it has posted no results.

The smaller, run by a research NGO, enrolled 20 people and was masked four ways. It completed in April 2024. It has posted no results and no publication has appeared.

The larger trial was not asking the question you think

Even if those results appear tomorrow, the bigger one will not settle whether ibogaine treats addiction.

Its primary outcome was a withdrawal severity score, averaged over days two to six. That measures whether the drug gets someone through detoxification comfortably. It is the part of the claim least in dispute, and it says nothing about whether they are using again three months later.

The question people actually have is the one no completed trial has been designed to answer.

The one randomised result that exists

There is a single randomised, double-blind, placebo-controlled study of an iboga alkaloid in opioid-dependent people, and it has been published.

It tested noribogaine, the metabolite, in twenty-seven patients at 60, 120 or 180 mg against placebo. It found a concentration-dependent lengthening of the QT interval, with mean prolongations of roughly 16, 28 and 42 milliseconds across the three doses. On withdrawal it found a trend that did not reach statistical significance.

That is the complete randomised evidence in a dependent population: a clear cardiac signal and no demonstrated benefit, in twenty-seven people.

What the observational literature does show, and where it stops showing it, is on ibogaine for opioid addiction.

The scale of the gap

The comparison is not rhetorical. These are counts from PubMed, from the trial registry and from the US regulator’s own database, taken on 25 August 2026. The PubMed figures come from searching each drug name in title or abstract, filtered to the randomised controlled trial publication type.

And the three ibogaine records indexed as randomised controlled trials are not efficacy trials. They are the noribogaine safety study above, a noribogaine study in healthy volunteers, and a 20 mg study in healthy volunteers that found minimal effect on mood or performance.

None of the three came from the four registered interventional studies in the row above. All three were registered in New Zealand, on the Australian New Zealand Clinical Trials Registry, and two of them were sponsored by DemeRx, Inc. of Fort Lauderdale, Florida. The randomised evidence base for iboga alkaloids was built by American companies, in trials run outside the United States, on a register most people auditing this field never open.

What the systematic reviews say about the evidence

Eight or nine reviews now exist. They differ in scope and agree almost entirely in verdict.

The most comprehensive count found 24 studies covering 705 people: seventeen open-label studies or case series, three case reports, one retrospective survey, and three controlled studies. Two deaths occurred within those 24 studies.

Those three controlled studies are the ones described above, and none of them tested ibogaine for efficacy in dependence. Two are noribogaine studies and the third was in healthy volunteers.

A 2025 review applying formal risk-of-bias tools across psychedelic treatments for opioid use disorder concluded that most studies had a high risk of bias, mostly from lack of randomisation and lack of blinding. A 2025 review in Addiction using Cochrane risk-of-bias assessment and GRADE identified its best evidence for psilocybin and ketamine and named no ibogaine randomised trial at all.

What is coming

Texas appropriated $50 million and its health commission selected UTHealth Houston to lead a public-university consortium, described on our Texas page. An appropriation, a selection and a disbursement are three different events, and only the first two have happened. The commission’s own page has said since at least May 2026 that “recent plans submitted to HHSC do not meet the requirements of Chapter 491, Health and Safety Code, including those related to matching state funds and allocation of revenue attributable to intellectual property and other rights”, and that the contract is not complete. No Texas-funded ibogaine trial is registered anywhere. Arizona awarded $5 million in August 2026 to a neurological institute for a phase 1/2 double-blind placebo-controlled trial in forty adults, which had not yet appeared on the registry when this page was compiled. And an independent group is recruiting for the first brain-imaging study of ibogaine not run by the team that produced all the existing imaging, with data expected no earlier than 2027.

All three are real, none has reported anything, and none has enrolled a participant. Fifty-five million dollars of state money has been announced across two states and produced no registered trial.

How to read a clinic that says “clinical trials”

The phrase is not false. Trials exist. What it obscures is the difference between a trial being registered and a trial having answered something.

Three questions separate the two.

1. Has it reported? The registry says, and for every ibogaine study it says no. Check the metabolite and the European register separately, because the two trials that did report are on neither the list nor the search term.
2. Was it randomised and blinded? Two of nine were. Neither has reported.
3. What was the outcome measured? Withdrawal over five days is not the same claim as abstinence at six months.

When it does not work covers what the uncontrolled follow-up studies found in the meantime, which is the best evidence that currently exists, and is not a substitute for the trials that have not reported.