Increased cortical thickness and decreased brain age among special operations veterans with blast TBI after a magnesium-ibogaine protocol
A new study by Geoly, Coetzee, Buchanan, et al. (2026), published in iScience, provides some of the first objective evidence of structural brain changes in humans following a single treatment with magnesium-ibogaine
Building on the clinical outcomes of the MISTIC (Magnesium-Ibogaine: the Stanford Traumatic Injury to the CNS) protocol, this specific paper shifts focus from psychological symptoms to brain morphometry (the physical structure of the brain).
The study utilised structural MRI scans (T1-weighted) at baseline, immediately post-treatment, and at a one-month follow-up for 30 Special Operations veterans. The primary findings include:
Reduction in "Brain Age": Researchers used machine learning to estimate "predicted brain age" (pBA). At the one-month mark, participants showed a significant decrease in brain age, averaging -1.3 years compared to baseline.
Increased Cortical Thickness: Longitudinal analysis revealed significant increases in cortical thickness across 11 distinct brain regions. This is notable because chronic TBI and blast exposure are typically associated with cortical thinning and atrophy.
Subcortical Volumetric Expansion: The study found significant volume increases in 8 subcortical regions. This suggests that the treatment may reverse some of the structural degradation caused by repetitive blast injuries.
Correlation with Clinical Gains: The structural "neurorepair" observed in the scans aligned with the rapid and sustained clinical improvements in PTSD, depression, and functional disability previously reported in this cohort.
The researchers also acknowledge potential limitations in the study, notably a Lack of a Control Group: As a prospective observational study, there was no placebo or "standard of care" control group. This makes it difficult to definitively attribute the structural changes solely to the ibogaine, as opposed to other factors in the treatment environment or natural recovery (though natural recovery of cortical thickness in chronic TBI is rare). The authors acknowledge that T1-weighted scans are sensitive to non-structural changes, such as shifts in brain hydration or vascularity. While the direction of the effect is consistent with neuroplasticity, it is not definitive proof of new neuronal growth (neurogenesis).
The "Magnesium" Factor: The protocol co-administers magnesium to mitigate ibogaine’s known cardiac risks (QT prolongation). While magnesium itself has neuroprotective properties, the study was not designed to decouple the effects of magnesium from the effects of ibogaine
Abstract
“ Ibogaine is a psychoactive alkaloid with therapeutic potential that may promote neuroplasticity. Its effects on human brain morphometry are unknown. Thirty Special Operations Forces veterans with prior blast-induced TBI participated in an observational study in which they received ibogaine co-administered with magnesium. Structural MRIs were collected at baseline (n = 25), initial post-treatment (n = 25), and 1-month post (n = 22). Longitudinal analyses assessed cortical thickness, subcortical volume, and predicted brain age (pBA), estimated from T1 scans. pBA was significantly reduced at 1 month relative to baseline (−1.3 years).
Cortical thickness analysis revealed post-treatment increases in 11 regions. Subcortical analyses revealed significant volumetric expansion in 8 regions. Magnesium-ibogaine therapy was associated with increased cortical thickness, subcortical expansion, and reduced pBA at 1 month. Although T1s are sensitive to nonstructural changes, the overall direction of effect is consistent with neuroplastic change. “
Geoly, A. D., Coetzee, J. P., Buchanan, D. M., et al. (2026). Increased cortical thickness and decreased brain age among special operations veterans with blast TBI after a magnesium-ibogaine protocol. iScience, 29(3), 115121. DOI: 10.1016/j.isci.2026.115121. Read Paper
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