Every major ibogaine study, summarized

Most human studies of ibogaine look at opioid use. In three of them, withdrawal eased within about three days [1][2][3]. A 2024 Stanford study of veterans with brain injuries found big drops in PTSD, depression and anxiety scores [4]. Ibogaine also slows the heart's reset between beats, so treatment needs heart checks first and a close watch throughout [5].

What have human studies of ibogaine found?

Human studies of ibogaine point in one direction. In people dependent on opioids, withdrawal fell sharply within days of a single treatment [1][2][3]. In veterans with brain injuries, scores for disability and mental health fell over the next month [4].

Most of this research follows treated people over time and records what changes [6]. The work took place in St Kitts, Mexico, New Zealand, the Netherlands, Brazil and the US [1][2][3][5][7][8].

People weighing ibogaine usually want two answers from each study. They want to know what it measured and what it found. The big picture is in the evidence overview for 2026.

The withdrawal finding shows up again and again. It appears in a Dutch university hospital [5]. It also appears in people treated in apartments and hotel rooms between 1962 and 1993 [7]. Former patients surveyed months or years later describe the same early relief [9].

How do researchers think ibogaine works?

Ibogaine acts on many brain targets at once [6]. It binds to opioid receptors, to the pumps that recycle serotonin and dopamine, and to several other receptor types [6]. A 2019 research paper calls the route to its effect on drug-seeking unresolved [6].

Most medicines are built to press one button. Ibogaine presses many at the same time. That makes it hard to trace any one effect back to one cause.

The body turns ibogaine into a second active compound, noribogaine. An enzyme called CYP2D6 does most of the work [1][10]. Ibogaine itself clears from the blood within a day in most people [1]. Noribogaine stays for days [11][12].

The team behind the St Kitts study points to noribogaine as the likely reason relief lasts longer than the first dose [1]. In rodent research, ibogaine's direct contact with receptors does not seem to explain its long-lasting effects [6].

Animal research backs up the withdrawal effect. In rodent studies, ibogaine eases withdrawal signs [6]. It also cuts how much morphine and heroin the animals choose to take [6]. The pharmacology of ibogaine has its own article.

What did each major ibogaine study find?

Each major opioid study found withdrawal easing soon after treatment [1][2][3][7]. Several also tracked drug use for months afterwards [2][3][9]. This opioid work largely predates the fentanyl era [13]. The table sets out who took part and how each study was run. The notes below cover what each one found.

Alper et al. 1999. This series gathered people dependent on heroin who were treated outside medical settings [7]. Most saw their withdrawal signs resolve within 24 hours, with no further drug-seeking over the next three days [7]. One person in the series died about 19 hours after the dose [7]. The post-mortem found no clear cause [7].

Mash et al. 2018. In a St Kitts inpatient unit, people dependent on opioids or cocaine took one dose under heart monitoring [1]. Doctors scored opioid withdrawal significantly lower 36 hours later [1].

Opioid craving fell by discharge [1]. Among those reached a month later, it was still lower [1]. The team recorded no serious adverse events [1].

Brown and Alper 2018. In Mexico, people dependent on oxycodone or heroin rated their own withdrawal [2]. Scores fell from 31 to 14 about three days after treatment [2]. Half reported no opioid use in the month that followed [2].

The improvement in drug-use scores peaked at one month [2]. A smaller improvement held from three to twelve months [2]. Scores for legal and family problems improved as well [2].

Noller et al. 2018. In New Zealand, where ibogaine is available on prescription, self-rated withdrawal fell from about 25 to 14 within a day [3]. A standard drug-use score fell from 0.32 to 0.06 over twelve months [3]. Depression scores fell from 22 to 4 [3]. At twelve months, three in four of those tested had urine free of opioids [3].

One person enrolled in the New Zealand study died during treatment [3]. The coroner judged the death very likely related to ibogaine, most probably through a heart rhythm problem [3].

Davis et al. 2017. Former patients of a Mexican clinic answered an online survey about their treatment [9]. Eight in ten said ibogaine eliminated or sharply reduced their withdrawal [9].

Three in ten said they never used opioids again [9]. About half said they went back to opioids but used less than before [9].

Schenberg et al. 2014. In Brazil, people who had used alcohol, cannabis, cocaine or crack took ibogaine with psychotherapy, and 61 percent were abstinent when the records were reviewed [8].

Rocha et al. 2026. In a hospital pilot in adults with alcohol use disorder, most said they drank less after ibogaine [14].

Knuijver et al. 2022. In a Dutch university hospital, people on methadone or buprenorphine switched to morphine, then took one dose [5]. Most did not go back to morphine over the next 24 hours [5]. This study's heart findings are covered below.

What did the 2024 Stanford study of veterans find?

In the 2024 Stanford study, veterans with brain injuries reported far less disability one month after ibogaine [4]. Their PTSD, depression and anxiety scores also fell sharply [4]. Most earlier ibogaine research had focused on addiction [4].

The veterans had served in special operations units. They had been near blasts many times in combat [4]. For most, the brain injuries were mild [4].

Many lived with PTSD, depression or anxiety at the start [4]. They were treated at a clinic in Mexico, where ibogaine use is not restricted [4].

Magnesium was part of the protocol. Each veteran received it through a drip before the dose and again about 12 hours later [4]. The aim was to protect the heart's rhythm, because ibogaine has been linked to fatal arrhythmias [4].

Screening came first. It included blood tests, a heart tracing, and a stop to drugs that clash with ibogaine [4].

On a standard disability scale, scores fell from 30 to 20 straight after treatment [4]. At one month they stood at 5, a level the authors describe as no disability [4].

Doctors' ratings of PTSD fell from 32 to 5 over the same month [4]. Depression fell from 26 to 4, and anxiety from 21 to 4 [4]. The authors call these effects large [4].

Thinking skills improved too. Processing speed and problem-solving scores rose, and no thinking skill got worse [4].

No serious or unexpected side effects occurred [4]. Staff watching heart monitors saw no clinically meaningful QT lengthening [4]. Every veteran had brief unsteadiness and tremor that cleared within a day [4].

Treatment came as a package. Group preparation and ceremony came before the dose [4]. The close read of the MISTIC study goes through it in detail.

What have studies measured about ibogaine and the heart?

Studies that measured the heart found that ibogaine and noribogaine both lengthen its electrical recovery time [5][11]. Doctors measure this as the QT interval. A long QT interval has been linked to sudden deaths after ibogaine [6].

The QT interval works a little like a camera flash. After each beat, the heart needs time to recharge before the next one. When that recharge runs long, the rhythm can go dangerously wrong [6].

In a Dutch hospital study, the QT interval rose by about 95 milliseconds at its peak [5]. Half the patients passed 500 milliseconds [5]. At that point, staff gave magnesium [5]. In close to half, the interval stayed long beyond the first day [5].

Noribogaine raises the QT interval on its own. Given to people coming off methadone, it lengthened the interval more at each higher dose [11].

Noribogaine also lingers. Its half-life in that study was 24 to 30 hours [11]. In healthy volunteers given small doses, the half-life ran from 28 to 49 hours [12].

Body chemistry changes the dose a person actually receives. When the CYP2D6 enzyme was blocked by another medicine, combined levels of ibogaine and noribogaine roughly doubled [10]. Between 5 and 10 percent of people of European descent lack the gene for this enzyme [3]. The researchers suggest genetic testing for it before treatment [10].

Screening and monitoring lower this risk without removing it [1][5]. The noribogaine pharmacokinetics article covers the long tail in more depth.

What do people in the studies say treatment is like?

People in the studies describe two main stages. First comes a vivid, dream-like stage. Then comes a calm, thoughtful one [1][7]. The first begins between about half an hour and three hours after the dose [1][7]. It lasts about 4 to 8 hours [1][7]. The second lasts roughly 8 to 20 hours [7].

In the first stage, people see a stream of images. Many are memories from their own past [7]. In St Kitts, people often said it felt like a waking dream or like watching a film [1]. Childhood memories came up for about four in ten [1]. In the Dutch hospital study, patients saw pictures behind closed eyes and relived vivid memories [5].

In the second stage, the images fade. Attention turns to what came up, and the mood is mostly calm [1][7]. Sleep is often hard for up to three days [7].

The body feels it too. In the Stanford study, every veteran was briefly unsteady on their feet [4]. Some needed treatment for headache or nausea during the session [4]. In St Kitts, nausea, vomiting and unsteady walking were the most common side effects [1].

Looking back, most people valued the experience. In St Kitts, nine in ten said it helped with their drug problem [1]. A similar share said it gave them insight [1]. Half said they felt cleansed or reborn [1].

In the Mexico survey, most former patients said they would make the same choice again [9]. Those whose drug use improved rated the experience as more spiritually meaningful [9].

Where the research goes next

The next step is a randomized controlled trial. The Stanford team calls for controlled trials to test both safety and benefit [4]. In opioid dependence, a trial against standard withdrawal care would show how much of the relief comes from ibogaine itself [1][2][3].

Such a trial has a design puzzle to solve. Ibogaine's experience is long and distinctive, which makes it hard to hide who received it [4]. Future designs will need a way to account for that.

Longer follow-up is the second direction. The Stanford results run to one month [4]. New Zealand showed that a twelve-month follow-up can be done [3].

Third is the heart. Magnesium co-dosing and continuous monitoring are now written into protocols [4][5]. Testing them side by side would show which approach keeps the QT interval in a safer range.

The last question is which compound does the work. Given on its own, noribogaine produced a trend toward lower withdrawal scores that did not reach statistical significance [11]. The relief may come from ibogaine, from noribogaine, or from both. The open questions article sets out what rigorous trials must answer.

Frequently asked questions

What did the Stanford ibogaine study find?

Veterans with brain injuries had large drops in disability, PTSD, depression and anxiety scores a month after treatment [4]. They took ibogaine with magnesium, and staff watched their heart rhythm the whole time [4]. None had a serious or unexpected side effect [4].

What is the success rate of ibogaine for opioid addiction?

Each study checked at a different time, so rates vary by study. In Mexico, half of those treated reported no opioid use at one month [2]. In a survey of former patients, about four in ten said they had gone six months or more without opioids [9].

Has ibogaine been tested in clinical trials?

Yes. Two trials of ibogaine in opioid dependence, one in Spain and one in the UK, are listed as completed, with no results posted yet [15][16]. The Spanish trial was randomised and masked, and the UK trial had a stage that compared ibogaine with a dummy pill [15][16]. Dummy-pill trials of noribogaine, the compound the body makes from ibogaine, have published results [11][12].

Does ibogaine work for depression and anxiety?

In the Stanford study of veterans with brain injuries, depression and anxiety scores fell sharply by one month [4]. In New Zealand, people treated for opioid dependence saw their depression scores fall over a year [3].

Is ibogaine safe?

Ibogaine lengthens the heart's QT interval, which has been linked to sudden deaths [6]. In one hospital study half the patients passed 500 milliseconds, and two studies here each had a death [3][5][7]. Screening and constant heart monitoring lower the risk without removing it [1][5].