Ivermectin and Multiple Sclerosis: Current Evidence
There is currently no established role for ivermectin in the treatment of multiple sclerosis in clinical practice, despite one promising preclinical study showing immunomodulatory effects in an animal model.
Evidence Overview
Preclinical Research Findings
The only relevant study identified is a 2023 experimental investigation that demonstrated ivermectin's potential immunomodulatory effects in experimental autoimmune encephalomyelitis (EAE), the mouse model of MS 1:
- Ivermectin reduced clinical symptoms of EAE by preventing inflammatory cell infiltration into the central nervous system 1
- The mechanism involved modulation of the Th17/Treg balance through the IL-2/STAT5 pathway, promoting regulatory T cells while inhibiting pro-inflammatory Th1 and Th17 cells 1
- In vitro effects included inhibition of T cell proliferation (CD3+, CD4+, CD8+), reduction of IFN-γ and IL-17A secretion, and increased IL-2 production and CD25 expression 1
Critical Limitations
This evidence cannot support clinical use for several important reasons:
- Animal models do not reliably predict human MS treatment efficacy - EAE differs substantially from human MS in pathophysiology and disease course 1
- No human clinical trials exist evaluating ivermectin for MS treatment or disease modification 2, 3, 4
- Ivermectin is FDA-approved only for parasitic infections (onchocerciasis and strongyloidiasis), with no proven therapeutic utility for neurological or autoimmune conditions 5, 6, 7
Established MS Treatments
Current evidence-based MS therapy includes six FDA-approved medications for relapsing forms of MS, with consensus supporting early treatment initiation 2:
- Disease-modifying therapies (DMTs) include interferons, glatiramer acetate, and monoclonal antibodies (natalizumab, alemtuzumab, ocrelizumab) 4
- No pharmacological agent has proven effective for secondary-progressive MS without relapses or primary-progressive MS (with one exception for primary progressive disease) 2, 4
Safety Considerations
Higher doses of ivermectin potentially needed for immunomodulatory effects may cause significant adverse effects 6, 7:
- Common side effects include dizziness, nausea, fever, headache, muscle/joint pain, and skin reactions 8
- Bioavailability increases 2.5-fold with high-fat food; should be taken on empty stomach 8
- Patients with severe liver disease face higher toxicity risk 8
Clinical Bottom Line
Do not use ivermectin for multiple sclerosis treatment outside of a rigorously designed clinical trial. The single preclinical study, while mechanistically interesting, provides insufficient evidence to justify human use 1. Patients with MS should receive established disease-modifying therapies with proven efficacy in reducing relapse rates and disease progression 2, 4. Using unproven treatments risks diverting resources and attention from evidence-based interventions that demonstrably improve morbidity and quality of life in MS patients 5.