A landmark study released today, Wednesday, February 18, 2026, has identified the shingles vaccine (Zostavax), the erectile dysfunction drug Viagra (sildenafil), and the motor neurone disease treatment riluzole as the most promising existing medications to repurpose for Alzheimer’s prevention. Led by the University of Exeter and funded by the Alzheimer’s Society, this major breakthrough suggests that repurposing these readily available drugs could fast-track effective dementia treatments by years.
The Shingles Vaccine: A Surprise Frontrunner
In a comprehensive review of over 80 existing pharmaceuticals, the research team pinpointed the shingles vaccine, specifically Zostavax, as the leading candidate for immediate clinical investigation. The findings, published in Alzheimer’s Research and Therapy, highlight a compelling correlation: individuals who received the vaccine showed a 16% lower risk of developing dementia compared to their unvaccinated peers.
The science behind this connection supports the growing "viral theory" of dementia. Researchers believe the immune response triggered by the vaccine may protect the brain against the inflammation and viral reactivation often linked to Alzheimer’s pathology. Because Zostavax is already approved and widely used for older adults, it offers a safety profile that experimental drugs cannot match.
Viagra and Riluzole: Beyond Their Original Uses
While the shingles vaccine leads the pack, the study also cemented the status of Viagra (sildenafil) and riluzole as critical players in Viagra dementia research 2026. Sildenafil, famously known for treating erectile dysfunction, has demonstrated a remarkable ability to increase blood flow to the brain and reduce the buildup of toxic tau proteins—a hallmark of Alzheimer’s disease.
Riluzole, currently the standard treatment for motor neurone disease (ALS), operates through a different mechanism. The Exeter team found that it helps regulate glutamate levels in the brain, preventing the excitotoxicity that kills neurons in dementia patients. Unlike new compounds that face a 10-15 year development pipeline, these drugs are available now, making them prime targets for repurposing drugs for healthy aging immediately.
Why Repurposing is the Future of Dementia Treatment
The traditional path to discovering new Alzheimer’s drugs is notoriously slow, expensive, and prone to failure. Developing a new drug from scratch often costs billions and takes over a decade. This study’s approach—systematically reviewing approved medicines—bypasses many of these hurdles.
Dr. Anne Corbett, Professor of Dementia Research at the University of Exeter, emphasized the urgency of this strategy. "Drug repurposing is a vital part of the mix, helping us turn today’s medicine for one condition into tomorrow’s treatment for another," she stated. By focusing on drugs with proven safety records in older populations, the research community can move directly to large-scale efficacy trials.
Next Steps: Clinical Trials and Patient Outlook
Following today's announcement, the research team is calling for immediate, large-scale clinical trials to verify these observational findings. For the millions of families navigating a dementia diagnosis, this offers a tangible glimmer of hope. Instead of waiting for a "miracle cure" that may be decades away, preventing Alzheimer's with existing medications could become a clinical reality within the next few years.
The identification of these three drugs marks a pivotal shift in how we approach neurodegenerative disease. As 2026 progresses, the focus will likely shift to how quickly these treatments can be integrated into standard preventative care for at-risk populations.
