Does Semaglutide (Wegovy) Reduce the Risk of Dementia?

By 
Dr Amit Kumar Singh
 on 
 • 
5
 min read

Dementia is one of the most pressing health challenges facing today. Dementia affects nearly 1 million people in the UK, a figure projected to rise to 1.6 million by 2040—it’s a crisis that touches countless families across the nation. Beyond its emotional toll, dementia places an immense economic burden on the country, with annual care costs exceeding £34 billion. Despite decades of research, treatments that significantly slow or prevent its progression remain elusive.

But a surprising development has recently sparked renewed hope. A medication originally developed for type 2 diabetes and obesity—semaglutide—has entered the spotlight for a completely unexpected reason. Several large studies suggest that people taking semaglutide may have a significantly lower risk of developing dementia. For a condition long associated with inevitable decline, this emerging data could mark the beginning of a new chapter in prevention and treatment.

Semaglutide is a GLP-1 receptor agonist, known by brand names such as Ozempic and Wegovy. It is approved for the treatment of type 2 diabetes on the NHS, and Wegovy is available for weight management under specific eligibility criteria. While it is not currently licensed to treat dementia, research is rapidly evolving, and new insights are challenging the boundaries of how we view this medication—and the very nature of cognitive decline.

The Emerging Evidence - What the Studies Are Showing

The recent surge in interest began with two major observational studies. One, conducted by researchers at Case Western Reserve University, analysed data from millions of patients in the United States and found that those taking semaglutide had a significantly reduced risk of developing Alzheimer’s disease and other forms of dementia. In some cases, the relative risk reduction was as high as 45%, particularly in individuals with type 2 diabetes.

Another influential study from the University of Galway echoed these findings. Their research demonstrated that older adults on GLP-1 medications like semaglutide were far less likely to develop dementia compared to those not on such treatments. Interestingly, the protective effect appeared to be especially strong among women and those aged over 65, and was particularly notable for vascular dementia, which is linked to problems in blood supply to the brain.

These early findings have sparked considerable excitement, but also warrant caution. After all, observational studies can only show association, not causation. Still, the consistency of results across large datasets, combined with a strong theoretical rationale, has led many researchers to believe that there may indeed be something uniquely protective about semaglutide regarding brain health.

So, how might this drug—primarily used to regulate blood sugar and support weight loss—help reduce dementia risk? The answers lie in how semaglutide works within the body and, increasingly, the brain. First and foremost, semaglutide improves metabolic health by helping regulate glucose and insulin levels. Both type 2 diabetes and obesity are established risk factors for dementia. By managing these conditions effectively, semaglutide may reduce the downstream damage that leads to cognitive decline.

Emerging research also highlights semaglutide’s role in reducing neuroinflammation, a process that damages brain cells and accelerates ageing. Some animal studies suggest it may even help clear out toxic proteins like amyloid and tau, hallmarks of Alzheimer’s disease. Additionally, semaglutide appears to enhance vascular function, potentially preventing the microvascular damage that contributes to memory loss and executive dysfunction. There’s also early evidence that it might promote neurogenesis, or the growth of new brain cells, particularly in regions responsible for memory.

To explore this further, randomised controlled trials are now underway, including two UK-based studies—EVOKE and EVOKE+. These trials are directly investigating whether semaglutide can delay the progression of early Alzheimer’s disease. Results from these trials, expected in the coming years, will provide the kind of high-quality evidence needed to determine whether semaglutide could become part of a new era in dementia prevention.

Understanding the Nuance: Important Considerations

While the headlines about semaglutide and dementia are encouraging, it’s essential to approach this topic with nuance and scientific rigour. So far, the strongest studies have been observational. That means they can detect trends in large populations, but they cannot definitively prove that semaglutide causes the reduced dementia risk. There may be confounding factors—perhaps people on semaglutide were more engaged with healthcare, or had other lifestyle factors that contributed to their lower risk.

This is why randomised controlled trials like EVOKE are so important. These studies compare groups of people receiving semaglutide versus a placebo, under controlled conditions. Only through these gold-standard trials can we determine whether semaglutide directly protects the brain or whether the observed benefits are due to improved metabolic control alone.

At present, semaglutide is licensed for people with type 2 diabetes who have not responded well to other treatments. Wegovy, the weight management version, is approved for people with a BMI of 30 or above, or 27 with weight-related comorbidities, such as hypertension or pre-diabetes. It is not yet licensed or recommended for dementia prevention, and it is not a treatment for cognitive impairment or memory loss.

Like any medication, semaglutide has potential side effects. The most commonly reported are gastrointestinal symptoms, including nausea, vomiting, diarrhoea, and constipation. Most of these are mild and tend to subside with time, but for some, they can be bothersome. Rare but more serious risks include pancreatitis and gallbladder issues. As with any new treatment, it’s crucial to weigh the benefits against the risks, and this is best done in consultation with a healthcare professional.

Conclusion

The idea that semaglutide might protect against dementia is both promising and unexpected. While more research is needed and it’s not yet licensed for this use, those taking it for diabetes or weight loss may see added benefits. Still, healthy habits—like managing weight, staying active, and engaging the mind—remain our best defense against cognitive decline. If you’re concerned about memory loss, talk to your GP—early action matters.

FAQs

1. Can semaglutide lower my risk of dementia?
Emerging research suggests that semaglutide may reduce the risk of developing dementia, particularly in people with type 2 diabetes. However, these findings are from observational studies, and more research from clinical trials is needed to confirm a direct protective effect.

2. How might semaglutide help protect the brain?
Semaglutide improves metabolic health, reduces inflammation, and may support blood vessel and brain cell function. These effects could help lower dementia risk, especially by addressing conditions like diabetes and obesity, which are known risk factors for cognitive decline.

3. Is semaglutide approved for dementia prevention in the UK?
No, semaglutide is not currently approved for preventing or treating dementia. In the UK, it is licensed for managing type 2 diabetes and obesity under specific NHS or private prescription criteria.

4. Should I take semaglutide to prevent dementia?
At this stage, semaglutide should only be taken for approved uses like diabetes and weight management. If you’re concerned about dementia, speak with your GP about evidence-based prevention strategies and whether semaglutide may be appropriate for your health needs.

References

  1. Xu, R., Nazif, B., Mohanty, A., Jambaulikar, G., Xie, J., Mason, C., ... & Lin, K. (2024). Associations of semaglutide with first‐time diagnosis of Alzheimer's disease in patients with type 2 diabetes: Target trial emulation using nationwide real‐world data in the US. Alzheimer’s & Dementia, 20(1), 14313. https://doi.org/10.1002/alz.14313 
  2. Meca, A. D. (2024). Unlocking the potential: Semaglutide’s impact on neurodegeneration and dementia. International Journal of Molecular Sciences, 46(6), 354. https://doi.org/10.3390/ijms46060354 
  3. Feng, L., McKee, S., Cirillo, C., Schieve, L. A., ... & Xu, R. (2025). Associations of semaglutide with Alzheimer's disease-related dementias in a nationwide population-based database. Journal of Alzheimer’s Disease, 97(2), 445–454. https://doi.org/10.3233/JAD-240515 
  4. Cummings, J. L., Atri, A., Feldman, H., Myers, J. P., Cordonnier, C., Kordower, J. H., ... & Toole, J. F. (2025). evoke and evoke+: Design of two large-scale, double-blind, placebo-controlled, phase 3 studies evaluating efficacy, safety, and tolerability of semaglutide in early-stage symptomatic Alzheimer’s disease. Alzheimer’s Research & Therapy, 17(1), 14. https://doi.org/10.1186/s13195-024-01666-7  
  5. Boboc, I. K. S., Moses, M. I. T., & Stefanescu, C. (2024). Exploring the impact of semaglutide on cognitive function and neuroinflammation in a mouse model of Alzheimer’s disease. Biomedicines, 12(12), 2689. https://doi.org/10.3390/biomedicines12122689
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