Aging Clinical Trials: TAME and Other Human Studies
What the TAME metformin trial plans to test and why it matters, plus a registry-based look at other human aging trials such as PEARL, CALERIE, MILES, ASPREE and DO-HEALTH.
Content last updated . This page has not been medically reviewed.
Why aging trials are different
Most trials test a treatment against one disease. Geroscience trials ask a bigger question: can an intervention that targets the biology of aging delay several age-related diseases together? A 2018 review described TAME (Targeting Aging with Metformin) as the first aging outcomes trial designed this way. [1] A 2025 JAMA review defines geroscience as aiming to slow age-related disability, prevent age-related diseases and increase disability-free survival. [2]Registry records and published papers can be read; headlines often blur what is planned with what is done. Below, each trial is labeled by what we could read this session. Nothing here advises use of any medicine. See Longevity Interventions: What Human Evidence Exists for results across interventions.
TAME: planned, with status unclear
What it plans to test. TAME was designed to test whether metformin, compared with placebo, reduces new age-related chronic disease in older adults without diabetes. [3] A description of the design reported about 3,000 participants and a double-blind, placebo-controlled, multi-site, six-year plan, with a combined outcome of new age-related disease or death; the authors also noted discussions with the FDA about a possible new indication. [4]Why it matters. Aging is not a listed use on the metformin drug information page we read. [5] A 2019 editorial said TAME and other trials have the potential to support aging as a treatment indication, but questioned whether its goals match the geroscience aim of extending healthspan. [6] See Is Aging a Disease?.
Status as read. A news report dated April 22, 2024 said the trial had not started, that the National Institute on Aging had set aside about $5 million against an estimated $45 to $70 million cost, and that it could begin when funding arrives. [7] We searched ClinicalTrials.gov for the trial name and did not find a TAME aging record. Current status: not verified. Do not confuse it with TAME-PKD, a separate metformin trial in polycystic kidney disease. [8]
Other human studies with registry records
| Study | What it tested | Size and status (registry) | What was reported |
|---|---|---|---|
| PEARL | Weekly low-dose rapamycin vs placebo, healthy older adults | 129 enrolled; completed | Main outcome (visceral fat) unchanged; safety similar to placebo over 48 weeks. [9][10] |
| CALERIE | Two years of 25% calorie restriction, adults without obesity | 238 enrolled in the registry record; completed | Achieved restriction about 12%; risk markers changed; lifespan untested. [11][12] |
| MILES | Metformin, older adults, gene-expression outcome | 16 enrolled; completed | Pilot design; primary outcome was gene expression in muscle and fat, not health events. [13][14] |
| ASPREE | Low-dose aspirin vs placebo, healthy older adults | 19,114 enrolled | No gain in disability-free survival; more major bleeding. [15][16] |
| DO-HEALTH | Vitamin D, omega-3, home exercise | 2,157 enrolled; completed | Post hoc analysis: omega-3 slowed some methylation clocks slightly. [17][18] |
| MASTERS | Metformin plus resistance training, adults 65 and older | Randomized, placebo-controlled | Metformin blunted muscle gain. [19] |
Registry sizes are the numbers listed on the record at the time we read it, and may differ from numbers in papers.
What these trials teach
- Outcome matters. ASPREE used a combined outcome of death, dementia or persistent disability, which is close to what people care about. [16] PEARL and MILES used body-composition or gene-expression outcomes, which are biomarkers. [9][13]
- Healthy volunteers are not patients. Results from people with a disease do not carry over to healthy adults, as the metformin editorial notes. [6]
- Small pilot trials show feasibility. A 12-person senolytic pilot was feasible but too small to judge benefit. [20] Senolytic studies continue; for example, one registry record lists a 30-person phase 2 study in chronic kidney disease, enrolling by invitation. [21]
- Biomarkers need validation. See Surrogate Endpoints and Aging Biomarkers in Trials.
For how to look up any trial yourself, read How to Find Longevity Studies and Trial Records. The metformin evidence is covered at Metformin and Aging Research.
Frequently asked questions
What is the TAME trial?
A planned placebo-controlled trial of metformin in older adults without diabetes, designed to test whether it delays several age-related diseases together. [1]
Has TAME shown that metformin slows aging?
No results from TAME were found. As of an April 2024 news report it had not started, and we could not verify a newer status. [7]
Which aging trial has the clearest result so far?
ASPREE gave a clear answer for low-dose aspirin in healthy older adults: no gain in disability-free survival and more major bleeding. [16]
Can I join or copy these trials?
Trials follow protocols with medical supervision. Talk with your own clinician and see the registry for any study that is recruiting.
References
- Justice JN et al. Development of clinical trials to extend healthy lifespan. Cardiovasc Endocrinol Metab 2018. PubMed 30906924. Read 2026-10-22.
- Kritchevsky SB, Cummings SR. Geroscience: a translational review. JAMA 2025. PubMed 40773213. Read 2026-10-22.
- Barzilai N et al. Metformin as a tool to target aging. Cell Metab 2016. PubMed 27304507. Read 2026-10-22.
- Justice JN et al. Development of clinical trials to extend healthy lifespan. Cardiovasc Endocrinol Metab 2018 (full text, PMC6428447). Read 2026-10-22.
- MedlinePlus (US National Library of Medicine). Metformin. Read 2026-10-22.
- Konopka AR, Miller BF. Taming expectations of metformin as a treatment to extend healthspan. GeroScience 2019. PubMed 30746605. Read 2026-10-22.
- WAMC / NPR. A cheap drug may slow down aging. A study will determine if it works. April 22, 2024. Read 2026-10-22.
- Perrone RD et al. Primary results of the randomized trial of metformin administration in polycystic kidney disease (TAME PKD). Kidney Int 2021. PubMed 34186056. Read 2026-10-22.
- ClinicalTrials.gov. NCT04488601, Participatory Evaluation (of) Aging (With) Rapamycin (for) Longevity Study. Registry record read 2026-10-22.
- Moel M et al. Influence of rapamycin on safety and healthspan metrics after one year: PEARL trial results. Aging (Albany NY) 2025. PubMed 40188830. Read 2026-10-22.
- ClinicalTrials.gov. NCT00427193, CALERIE. Registry record read 2026-10-22.
- Ravussin E et al. A 2-year randomized controlled trial of human caloric restriction: feasibility and effects on predictors of health span and longevity. J Gerontol A 2015. PubMed 26187233. Read 2026-10-22.
- ClinicalTrials.gov. NCT02432287, Metformin in Longevity Study (MILES). Registry record read 2026-10-22.
- Mohammed I et al. A critical review of the evidence that metformin is a putative anti-aging drug that enhances healthspan and extends lifespan. Front Endocrinol 2021. PubMed 34421827. Read 2026-10-22.
- ClinicalTrials.gov. NCT01038583, Aspirin in Reducing Events in the Elderly (ASPREE). Registry record read 2026-10-22.
- McNeil JJ et al. Effect of aspirin on disability-free survival in the healthy elderly. N Engl J Med 2018. PubMed 30221596. Read 2026-10-22.
- ClinicalTrials.gov. NCT01745263, DO-HEALTH. Registry record read 2026-10-22.
- Bischoff-Ferrari HA et al. Individual and additive effects of vitamin D, omega-3 and exercise on DNA methylation clocks of biological aging in older adults from the DO-HEALTH trial. Nature Aging 2025. PubMed 39900648. Read 2026-10-22.
- Walton RG et al. Metformin blunts muscle hypertrophy in response to progressive resistance exercise training in older adults (MASTERS trial). Aging Cell 2019. PubMed 31557380. Read 2026-10-22.
- Nambiar A et al. Senolytics dasatinib and quercetin in idiopathic pulmonary fibrosis: results of a phase I randomized placebo-controlled pilot trial. EBioMedicine 2023. PubMed 36857968. Read 2026-10-22.
- ClinicalTrials.gov. NCT02848131, Senescence in Chronic Kidney Disease. Registry record read 2026-10-22.