Noribogaine: how long does ibogaine's metabolite last?

Noribogaine is the compound the body makes from ibogaine. An enzyme called CYP2D6 does the work [1]. Ibogaine leaves the blood within about a day [1]. Noribogaine stays far longer. Its half-life was 28 to 49 hours in healthy volunteers [2], and 24 to 30 hours in people dependent on opioids [3]. Researchers propose that it carries ibogaine's longer-lasting effects [1].

What is noribogaine?

Noribogaine is the main active compound the body makes from ibogaine [1]. The change is small. An enzyme snips one tiny piece, called a methyl group, off each ibogaine molecule [1]. What is left is noribogaine [1]. Its chemical name is 12-hydroxyibogamine [1].

The conversion happens in the gut wall and the liver, soon after a person swallows a dose [1]. In Dutch patients given ibogaine, a model fitted to blood samples put the typical noribogaine peak at about seven and a half hours after the dose [4]. The same model put ibogaine's own peak much sooner, within about the first hour [4].

Noribogaine's peak was lower, a little over a quarter of ibogaine's [4]. It then stayed in the blood far longer [1].

Noribogaine is active in its own right. Given alone to people coming off methadone, it lengthened the heart's QT interval, and the effect grew with the dose [3].

People reading about ibogaine often ask why its effects seem to outlast the drug. Researchers look first at noribogaine's long stay in the body [1]. The wider picture of ibogaine's targets and metabolism is in The Pharmacology of Ibogaine, and the overall evidence is in Ibogaine: What the Evidence Shows in 2026.

How does the body turn ibogaine into noribogaine?

The body converts ibogaine to noribogaine with an enzyme called CYP2D6, found in the gut wall and liver [1][4]. The handover is quick.

In patients treated in St Kitts, ibogaine's half-life in the blood averaged 1.6 to 6 hours [1]. In people whose CYP2D6 works at a fast or intermediate speed, more than 90 percent of the ibogaine was gone 24 hours after the dose [1]. Noribogaine levels were still raised at that point [1].

The research group that first identified noribogaine describes ibogaine as a pro-drug [1]. A pro-drug is a compound the body turns into a second one that does much of the work.

A match and a log make a fair picture. Ibogaine is the match. It flares fast and burns out within hours. Noribogaine is the log it lights, which keeps burning slowly for days [1][2].

The body then processes noribogaine one step further. It attaches a sugar-based molecule, forming noribogaine glucuronide [4]. In Dutch patients with opioid use disorder, levels of this third compound stayed small through the first day [4].

Added up over time, the typical patient's total exposure to noribogaine ran a little higher than the exposure to ibogaine [4].

How long does noribogaine stay in the body?

Noribogaine has a half-life of roughly one to two days. In healthy men given noribogaine directly, its half-life averaged 28 to 49 hours across dose groups [2]. In people dependent on opioids, switched from methadone to morphine, it was 24 to 30 hours [3].

The two figures come from different groups of people, and each holds for its own group. Both place noribogaine's half-life at a day or more [2][3].

Half-life is the time the body takes to clear half of what is there. Picture a tank that drains at a steady rate. After one half-life, half the water is left. After two, a quarter is left. After three, an eighth. With a half-life of a day or two, noribogaine takes several days to fall to low levels [2][3].

Taken by mouth on its own, noribogaine was absorbed fast. Levels peaked two to three hours after the dose [2]. Higher doses produced proportionally higher levels in the blood [2].

Noribogaine spreads widely into the body's tissues. Pharmacologists estimate this with a figure called the volume of distribution. For noribogaine it averaged between about 1,400 and 3,100 litres across dose groups [2]. No body holds that much fluid. A figure that large means most of the drug sits in tissues rather than in the blood, the way water soaks into a sponge [2].

Does noribogaine explain why ibogaine's effects outlast the drug?

Researchers propose that it does, and the idea rests on timing. Ibogaine is mostly gone from the blood within a day, while noribogaine is still there [1]. The idea is plausible. Human blood tests and animal studies both lend it support [1][7].

The St Kitts research team makes this case. To them, ibogaine's short half-life meant the lasting after-effects likely came from noribogaine acting in the brain [1].

People considering treatment often ask what happens in the days after the dose. In the St Kitts patients, the withdrawal signs doctors scored stayed mild and did not flare up at later time points [1]. The team linked that steady course to noribogaine's long half-life [1]. How Ibogaine Interrupts Opioid Withdrawal covers the candidate mechanisms for the withdrawal effect itself.

In one study of veterans with brain injuries, care went on after the dose [9]. It included coaching from a licensed therapist and integration activities [9].

In rodents, ibogaine's own half-life is one to two hours [8]. Nineteen hours after rodents received ibogaine, their brain tissue held no noticeable amount of noribogaine [8].

Rodent studies show noribogaine acting on withdrawal directly. In mice dependent on morphine, noribogaine given by mouth reduced the withdrawal signs set off by an opioid blocker, by up to 88 percent [7]. Taken by mouth, it reached the rodent brain at about seven times its level in the blood [7]. From these rodent results, the authors judged that the metabolite, not ibogaine itself, drives this effect on withdrawal [7].

Why does ibogaine last longer in some people than others?

The speed of the CYP2D6 enzyme differs from person to person, and it sets how fast ibogaine is cleared [4][6]. In patients with opioid use disorder, ibogaine clearance varied more than tenfold across the range of CYP2D6 genetic types [4].

Think of CYP2D6 as the checkout lanes in a shop. Some people have many lanes open, and ibogaine moves through quickly. Others have few or none. Between 5 and 10 percent of people of European descent have no working CYP2D6 at all [5][10].

Slow processing changes the timeline. In healthy volunteers whose CYP2D6 had been blocked with the antidepressant paroxetine, ibogaine's half-life stretched to about 10 hours [6]. It was still detectable in their blood three days after the dose [6]. Their combined exposure to ibogaine and noribogaine was about twice as high as in volunteers without the blocker [6]. Their exposure to noribogaine alone was about the same [6].

The authors suggested genotyping people before treatment. They also suggested at least halving the dose for people with little CYP2D6 activity [6].

The same enzyme breaks down about 30 percent of medicines in current use [5]. A review of ibogaine's heart effects notes that methadone slows CYP2D6, so it is likely to slow ibogaine's breakdown too [5].

Ibogaine levels also shape the heart effect. In Dutch patients, QT lengthening and unsteadiness on the feet tracked ibogaine blood levels during the first day, more closely than noribogaine levels [4]. Slow processors keep ibogaine in the blood for longer [4][6].

The heart effect outlasts ibogaine itself. QT prolongation after ibogaine typically lasts more than 24 hours [5]. In a Dutch hospital study, it lasted beyond the first day in close to half the patients [11]. In case reports, it has sometimes persisted for more than a week [5].

Deaths linked to ibogaine have been reported from about an hour and a half to around three days after it was taken [5]. Cardiac events can occur several days, and in some cases weeks, after intake [5].

What does ibogaine feel like as the levels rise and fall?

The experience comes in two stages, and they line up with the drug's timeline. A vivid, dream-like stage comes first. A calm, thoughtful one follows [1][12].

The first stage begins between about half an hour and three hours after the dose [1][12]. This stage lasts about 4 to 8 hours [1][12]. It covers the first hours after dosing, when ibogaine levels are highest [4].

Body chemistry shapes this stage. Two people in St Kitts cleared ibogaine so fast that blood tests could not find it [1]. Neither reported the dream-like state [1].

People describe a stream of pictures, many of them memories. One classic account calls it panoramic recall of past life events [12]. Many say it feels like a waking dream [1].

The second stage lasts roughly 8 to 20 hours [12]. The images thin out. Attention turns to sorting through what came up, and the mood is mostly calm and neutral [12]. By then ibogaine is falling and noribogaine is near its peak [4].

The body feels it too. In a Dutch hospital study, every patient had a spell of severe unsteadiness and could not walk without help [11]. The unsteadiness was temporary [11].

Some people still feel mild effects a day after the dose, and these soon fade [1]. Sleep is often hard for up to three days, and sleep medicine helps [12]. Every Major Ibogaine Study, Summarized gathers the studies behind these accounts.

Where the research goes next

Three directions stand out. The first is tying blood levels to outcomes over several days. In a Dutch study, how severe withdrawal was did not track the level of either drug in the first 24 hours [4]. The authors suggest the dose may have sat at the top of the effect curve [4]. They call for rating withdrawal more often and for longer [4]. Sampling that runs for days would match noribogaine's half-life [2][3].

The second is dosing by genetic type. Two research teams have proposed lower doses for people with little CYP2D6 activity, guided by a gene test [4][6]. Trials can now test whether lower, tailored doses keep the benefit while easing the strain on the heart [4].

The third is noribogaine as a medicine in its own right. In healthy men, single doses from 3 to 60 mg were well tolerated [2]. They had no opioid-like effects on pupil size or pain tests [2]. In its first trial in patients coming off methadone, the most common side effects were changes in how light looked, headache and nausea [3]. In those patients, a trend toward lower withdrawal ratings did not reach statistical significance [3]. Whether the benefit holds without the acute ibogaine experience is still open. Beyond Ibogaine: Tabernanthalog and Engineered Analogs covers engineered relatives of ibogaine. Open Questions: What Rigorous Ibogaine Trials Must Answer sets out what trials need to settle.

Frequently asked questions

What is the half-life of noribogaine?

In healthy men given noribogaine directly, its half-life averaged 28 to 49 hours [2]. In opioid-dependent patients switched from methadone to morphine, it was 24 to 30 hours [3]. Ibogaine's own half-life in treated patients averaged 1.6 to 6 hours [1].

How long does noribogaine stay in the body?

With a half-life of one to two days, noribogaine takes several days to fall to low levels [2][3]. In patients given ibogaine, noribogaine was still raised 24 hours after the dose, when most of the ibogaine was gone [1].

What is the difference between ibogaine and noribogaine?

Noribogaine is the compound the body makes from ibogaine by removing one methyl group [1]. Ibogaine is short-lived and noribogaine lasts for days [1][2]. In patients during the first day, QT lengthening and unsteadiness tracked ibogaine levels more closely than noribogaine levels [4].

What does CYP2D6 have to do with ibogaine?

CYP2D6 is the enzyme that turns ibogaine into noribogaine [1]. Its speed is set partly by genes, and it changed ibogaine clearance more than tenfold across patients [4]. When CYP2D6 was blocked, combined exposure to ibogaine and noribogaine about doubled [6].

How long do the effects of ibogaine last?

The vivid first stage lasts about 4 to 8 hours, and a calmer, reflective stage follows for roughly 8 to 20 hours [12]. Sleep can be hard for up to three days [12]. QT lengthening, the heart effect, typically lasts more than 24 hours [5].

Is ibogaine dangerous?

Ibogaine lengthens the heart's QT interval, which has been linked to sudden deaths [8]. In one hospital study, patients were screened beforehand and closely monitored, and half still passed a QT of 500 milliseconds after a single dose [11]. Cardiac events can occur several days, and in some cases weeks, after intake [5].