The Food and Drug Administration is asking the public to weigh in on how to run early ibogaine trials, including a starting dose no higher than 10 milligrams per kilogram and days of heart monitoring. Comments are due Nov. 20 under docket FDA-2026-N-10429.
What the FDA is Asking about Ibogaine Trials
The agency announced the request for information on Oct. 5 in a press release. The Federal Register notice was scheduled for publication Oct. 6, and the comment period runs 45 days from that date. Forty-five days after Oct. 6 is Nov. 20, which leaves 38 days from today. The FDA said late comments will not be considered. People can file them at regulations.gov or by mail to the agency’s Dockets Management Staff in Rockville, Maryland.
The notice covers early-phase trials of ibogaine drug products. It asks for comment on dose selection, care setting, safety monitoring, who should qualify, when to stop a trial and who should oversee it. It excludes questions about drug scheduling, legalization and personal or religious use.
The notice states that its contents do not set legally enforceable requirements. The trial design it lays out is a set of proposals. Michael Davis, director of the FDA’s Center for Drug Evaluation and Research, said in the release that “there are important scientific questions as well as serious safety concerns” with ibogaine.
Why Ibogaine Needs Heart Monitoring
The FDA’s notice is blunt about the risks. It says clinical data “have shown that ibogaine has serious cardiovascular risks.” Ibogaine commonly causes a large lengthening of the QTc interval, a measure of how long the heart takes to reset between beats. A long QTc can trigger torsades de pointes, a dangerous rhythm that can lead to death.
The agency says the link was identified after a 1993 advisory committee meeting on an ibogaine application for cocaine dependence, where members focused on how little room there was between a helpful dose and a toxic one.
The notice also cites nervous system effects. It says changes in perception, impaired thinking and loss of coordination are common. In a 2022 study of a 10 mg/kg dose in people with opioid use disorder, every participant had severe but temporary ataxia, the notice says. In animal studies, it reports dose-related toxicity that ranges from tremors and ataxia at lower doses to damage to nerve cells, convulsions and death at higher ones, with the cerebellum affected.
The notice points to a forensic review of ibogaine-linked deaths published in 2012 but gives no case count. It says the published literature often lacks a description of the products used and data on individual participants. That gap is one reason the agency is asking for data from treatment settings outside the United States.
Ibogaine is broken down by the liver enzyme CYP2D6 into noribogaine, which is the active metabolite. The body clears it slowly and the effects last days. For that reason the plan proposes testing participants for CYP2D6 and enrolling only fast and intermediate metabolizers.
How the Ibogaine Dose Cap Works
The FDA says doses from 5 to 20 mg/kg appear in published clinical reports, and that available animal data show these doses lack adequate safety margins. It proposes that a first dose be justified by the literature and not exceed 10 mg/kg.
The range matters because dose is counted per kilogram of body weight. For an adult who weighs 154 pounds, about 70 kilograms, the proposed ceiling is 700 milligrams. The top published dose of 20 mg/kg would be 1,400 milligrams for the same person, twice the ceiling. The published range itself spans a factor of four, from 5 to 20.
The proposed design is slow by drug-trial standards. Groups would be small and dose in steps upward, with each person given a single dose. Within a group, participants could be dosed one at a time. An increase for the next group would need review by a safety committee, an independent data and safety monitoring board and the FDA. The agency also asks whether total body weight, lean body weight or a target blood level is the better way to set doses.
Who Would Qualify for an Ibogaine Trial
The notice describes two groups. One is adults with moderate to severe post-traumatic stress disorder lasting at least six months that has not responded to an SSRI and psychotherapy. The other is adults with moderate to severe opioid use disorder who have not reached sustained remission despite adequate treatment. The release says the Department of Health and Human Services is prioritizing those same two groups for federally backed research.
Participants could be 18 to 55 and off psychiatric medicines. The FDA expects to exclude anyone with a baseline QTcF of 430 milliseconds or more, a heart-rhythm reading corrected for heart rate. Other likely exclusions include structural heart disease, arrhythmia history, seizures, psychosis, bipolar disorder, recent suicidal thoughts, balance disorders, significant liver or kidney impairment, and pregnancy or breastfeeding.
Drugs that lengthen QTc or slow the heart rate would have to stop first. The notice lists methadone, buprenorphine, antipsychotics and SSRIs among those that interact.
Dosing would take place in an inpatient unit with continuous rhythm monitoring, staff trained in advanced cardiac life support, a bedside defibrillator, pacing and ventilator support. Monitoring would begin at dosing and could last as long as 36 hours, until rhythms are normal and QTc has returned near its starting value. Discharge would follow criteria such as a 48-hour 12-lead electrocardiogram showing no QTc prolongation. The notice suggests cognitive testing could continue for up to 12 months.
Dosing would pause if a participant’s QTc stays above 500 milliseconds for more than two days. The same applies to a sustained dangerous arrhythmia, a seizure, new suicidal thoughts, lasting disturbances in perception, or a death or serious adverse event that may be related to the drug.
The Federal Push Behind the Ibogaine Request
The request follows Executive Order 14401, signed April 18. The order directs the FDA and the Drug Enforcement Administration to build a Right to Try pathway for psychedelic drugs, including ibogaine compounds. It also tells HHS to set aside at least $50 million through the Advanced Research Projects Agency for Health to support state programs.
Six days later, the FDA announced that it had allowed an early-phase study of noribogaine, an ibogaine derivative made by DemeRx NB, to proceed for alcohol use disorder. The agency called it the first time it had allowed a U.S. study of an ibogaine derivative and said the decision did not mean the drug was safe or effective. In July the FDA finalized its guidance on psychedelic drug trials. The National Institute on Drug Abuse is funding ibogaine research for opioid use disorder, the release says.
The notice also says the agency welcomes investigational new drug applications for ibogaine products. Questions about the request go to the FDA’s ibogaine mailbox at IbogaineRFI@fda.hhs.gov.
