The FDA will formally halt or restrict at least one ibogaine drug trial (called a clinical hold) or issue safety guidance because of a cardiac problem called QT prolongation — a heartbeat irregularity that can cause sudden death. Ibogaine is known to affect the heart's electrical system, and researchers have already documented this risk in peer-reviewed studies. The FDA uses this evidence to trigger safety holds.
A growing body of peer-reviewed cardiac complication data — specifically QT prolongation — constitutes the evidentiary record FDA reviewers require to justify a clinical hold. QT prolongation is a documented regulatory tripwire across therapeutic classes. Active ibogaine INDs face this risk asymmetrically given the compound's known cardiac ion-channel effects. The question is timing and which program is first, not whether it will happen.