- 114studies in the library match, of 29,780
- 67name it in the title
- 2000–2026years published
- 111peer-reviewed articles
The query: title or abstract mentions "metformin", matched case-insensitively against each record's title and abstract (its summary field) in alzhub's library of 29,780 study records, as of 2026-11-09. Every count on this page comes from that match. The matched list as JSON.
Type 2 diabetes raises dementia risk, so the drugs that treat it are natural candidates for protecting the brain. Metformin acts on energy metabolism and inflammation in ways that are plausible for Alzheimer's, and cohort studies have compared dementia rates in people taking metformin with those on other diabetes drugs. Those comparisons are hard to interpret because metformin is given earlier in diabetes and to healthier kidneys. Small trials have tested it directly in people with memory problems, and a larger one is under way.
This page describes what published research in alzhub's library reports. It is not medical advice and does not apply to any one person: a doctor who knows the person's history is the only one who can say what a result or a treatment means for them.
What the studies report, in their own words
Whole sentences copied from the abstract or key findings of the highest-scoring matched studies, chosen because they mention the subject and give a figure. 8 of the 114 matched records are quoted; each links to its study page and from there to the paper.
“Due to the consistent increase in A. muciniphila and decrease in R.ilealis in people with T2D subjects treated with metformin, we investigated the association between this ratio and cognition.”
“DPP-4 inhibitors, metformin, thiazolidinedione, and sulfonylurea exhibited a significant impact on the risk of dementia in diabetics compared with insulin (HR, 0.35; 95%CI, 0.20-0.59, HR, 0.48; 95% CI, 0.30-0.77, HR, 0.45; 95% CI, 0.29-0.73 and HR, 0.55; 95% CI, 0.34-0.88, respectively).”
“Metformin, thiazolidinediones, pioglitazone, GLP1RAs and SGLT2is were associated with significant reduction in risk of dementia.”
“Metformin could not be tolerated by 7.5% of participants; 15% tolerated 500 mg/day, 35% tolerated 1000 mg/day, 32.5% tolerated 1500 mg/day, and only 10% tolerated the maximum dose.”
“Eleven (64.7%) studies reported a reduced risk of dementia associated with metformin use; two (11.8%) suggested metformin increased dementia risk, while four (23.5%) concluded no significant associations.”
“For T2DM, compared with no medication, sulfonylureas alone reduced the HR from 1 to 0.85 (0.71–1.01), metformin alone to 0.76 (0.58–0.98), while with combined oral therapy the HR was 0.65 (0.56–0.74).”
“During the 12-year follow-up, the metformin cohort exhibited a higher risk of PD than the nonmetformin cohort (hazard ratio [HR]: 2.27, 95% confidence interval [CI]=1.68-3.07).”
“Compared with non-sulfonylurea oral agents (e.g., metformin), other treatment regimens were more likely to be deintensified (aRR = 1.31-1.88), except for basal insulin (aRR = .59; 95% CI = .52-.66).”
What kind of evidence it is
By study design
| Design (as recorded) | Studies |
|---|---|
| Systematic review or meta-analysis | 12 |
| Other clinical trial | 1 |
| Cohort or longitudinal study | 13 |
| Case-control study | 3 |
| Cross-sectional study | 1 |
| No design recorded | 84 |
The design is the one named in alzhub's record for the study; a record with none is counted as "no design recorded".
By year
| Year | Studies | Share |
|---|---|---|
| 2026 | 6 | |
| 2025 | 18 | |
| 2024 | 15 | |
| 2023 | 12 | |
| 2022 | 10 | |
| 2021 | 8 | |
| 2020 | 11 | |
| 2019 | 7 | |
| 2018 | 3 | |
| 2017 | 6 | |
| 2016 and earlier | 18 |
Other counts within the matched set
| Peer-reviewed articles | 111 |
| Marked open access in the record | 29 |
| Rated "high" evidence strength in alzhub's summary | 23 |
| Rated "moderate" evidence strength in alzhub's summary | 15 |
| Rated "low" evidence strength in alzhub's summary | 73 |
| No evidence-strength rating | 3 |
| Records stating a participant count | 32 |
| Median participants (those records) | 3,042 |
| Largest participant count | 3,463,100 |
Within the 114 matched studies
| Studies… | Count | Rule |
|---|---|---|
| …that compare with a sulfonylurea or insulin | 55 | the abstract also contains "sulfonylurea" or "insulin" |
| …that are randomised trials or mention one | 20 | the abstract also contains "randomised" or "placebo" |
| …that report a hazard ratio | 13 | the abstract also contains "hazard ratio" or "HR" |
The 10 highest-scoring matched studies
Title matches first, then by alzhub's usefulness score, which rates a study's design, journal, evidence and recency, not whether its result is good news.
- Metformin-induced changes in the gut microbiome and plasma metabolome are associated with cognition in men
- Metformin in Amnestic Mild Cognitive Impairment: Results of a Pilot Randomized Placebo Controlled Clinical Trial
- Metformin and Dementia Risk: A Systematic Review with Respect to Time Related Biases
- Effects of the Insulin Sensitizer Metformin in Alzheimer Disease: Pilot Data From a Randomized Placebo-controlled Crossover Study
- Incidence of dementia is increased in type 2 diabetes and reduced by the use of sulfonylureas and metformin
- Effects of metformin exposure on neurodegenerative diseases in elderly patients with type 2 diabetes mellitus
- Metformin Cessation and Dementia Incidence
- Metformin Use Associated with Reduced Risk of Dementia in Patients with Diabetes: A Systematic Review and Meta-Analysis
- Association of Metformin use with risk of dementia in patients with type 2 diabetes: A systematic review and meta-analysis
- Long-term metformin usage and cognitive function among older adults with diabetes
Systematic reviews and meta-analyses in the set
12 of the matched records are recorded as a systematic review, meta-analysis or umbrella review; the highest-scoring not already listed above:
- Impact of antidiabetic agents on dementia risk: A Bayesian network meta-analysis
- Diabetes, antidiabetic medications and risk of dementia: A systematic umbrella review and meta-analysis
- Comparative efficacy and acceptability of antidiabetic agents for Alzheimer's disease and mild cognitive impairment: A systematic review and network meta-analysis
- Cardioprotective Glucose-Lowering Agents and Dementia Risk: A Systematic Review and Meta-Analysis
- Drug Repurposing in Oncology: A Systematic Review of Randomized Controlled Clinical Trials
Newest matched studies
- Effect of Metformin on tau pathology and proteostasis in cellular and a Drosophila model of Tauopathy
- Antidiabetic medications and risk of cognitive disorders in type 2 diabetes: A retrospective cohort study
- Randomized metformin and cognitive outcomes in the Diabetes Prevention Program Outcomes Study
- Legacy neuropsychiatric benefit after semaglutide is linked to maximum achieved dose and independent of the maximum weight lost
- Comprehensive Review on Alzheimer Disease: Causes, Risk Factors, Pathology, Mechanisms
Journals with the most matched studies
| Journal | Studies |
|---|---|
| Journal of Alzheimer's disease : JAD | 6 |
| Alzheimer disease and associated disorders | 2 |
| Annals of Internal Medicine | 2 |
| Diabetes care | 2 |
| Diabetes, obesity & metabolism | 2 |
Questions
- Does metformin protect against dementia?
- Cohort studies disagree, and the comparison is biased by who gets metformin. Randomised trials are the only way to settle it; the ones completed so far are small. The quoted papers report what each design found.
- How many studies on metformin and dementia does alzhub hold?
- 114 of the 29,780 study records in alzhub's library match the query "title or abstract mentions "metformin""; 67 of them name it in the title. Counted from the records when this page was built.
- What kinds of study are they?
- 12 systematic review or meta-analysis, 1 other clinical trial, 13 cohort or longitudinal studys, 3 case-control studys, 1 cross-sectional study; 84 record no design.
- What is the most recent study in the set?
- "Effect of Metformin on tau pathology and proteostasis in cellular and a Drosophila model of Tauopathy" (Research Square, 2026), the newest by publication date among the matched records.
- Which journals publish most on it?
- Journal of Alzheimer's disease : JAD (6); Alzheimer disease and associated disorders (2); Annals of Internal Medicine (2), counted across the matched records.
Read on
- Diabetes and Alzheimer'sThe condition metformin treats.
- Semaglutide and GLP-1 drugsThe other diabetes drugs in dementia trials.
- Treatments and medicinesWhat is approved and what is being tested.