Is There a Pill That Slows Aging? What the Trials Measured

The search terms are honest about what people want: "rapamycin for longevity", "metformin anti-aging", "TAME trial results", "klotho gene therapy". Under all of them sits one question: is there already a drug shown to extend healthy human life? On the trials that exist, no — and what they measured instead is the useful part.

This material is informational: it does not replace a consultation with a physician, and two of these drugs are prescription medicines licensed for entirely different diseases.

What would such a drug have to show?

Aging is not a condition regulators license drugs against, and "rate of aging" is not a validated endpoint in any trial below. That decides what a study can claim. A trial can measure a scan, a blood marker, a questionnaire, a vaccine response or a tissue stain — all faster than measuring whether people get fewer diseases or live longer. The only study designed around real disease outcomes, TAME, has no result. So for every number below, ask which kind of endpoint produced it.

Rapamycin: what did the longest controlled trial in healthy adults find?

PEARL, published in Aging (Albany NY) on 4 April 2025, is the longest placebo-controlled study of rapamycin aimed at healthy aging: randomised, double-blind, decentralised, 48 weeks, in healthy adults described as normative aging, on weekly compounded rapamycin at 5 or 10 mg or placebo.

The pre-specified primary endpoint was change in visceral fat on a DXA scan. It did not move: ηp² = 0.001, P = 0.942. That null result is the headline. The analysis covers 114 completers; the abstract does not give the number randomised, so it is not stated.

Adverse and serious adverse events were similar across groups and blood tests stayed within normal ranges. Several secondary findings were significant, all in completers: on 10 mg, a lean-tissue signal in women (ηp² = 0.202, P = 0.013) and less self-reported pain (ηp² = 0.168, P = 0.015); on 5 mg, better self-reported general health across both sexes (P = 0.004) and emotional well-being, which also improved in the placebo group (P = 0.023 and P = 0.019 respectively) — so on that scale the groups do not differ from each other. The odds ratio for lean mass in women was 28, 95% CI 2.42 to 323.7 — that width is what a small sample looks like. One signal pointed the other way: on 5 mg, an odds ratio of 0.24 (95% CI 0.06 to 0.93) on bone density, in the sample as a whole rather than in a sex-split column.

Neither the dose nor the schedule for taking it for longevity is established: PEARL tested two weekly doses and did not move its primary endpoint, and its authors write plainly that evaluating a broader range of doses and establishing efficacy is left to future work. There was no mortality or disease-onset endpoint, and 48 weeks cannot see rare or late harm. Weekly compounded rapamycin in healthy volunteers is also not transplant-dose sirolimus — what the molecule is approved for, alongside lymphangioleiomyomatosis.

Is everolimus the same thing?

Everolimus, an approved transplant and oncology drug acting on the same pathway, is cited here on two immune studies: a short course before influenza vaccination in older volunteers gave roughly a 20% higher antibody response (Mannick, 2014), and six weeks of low-dose everolimus plus BEZ235 — an experimental inhibitor never approved — in 264 older adults was associated with fewer self-reported infections over the next year (P = 0.001) and a better flu-shot response (Mannick, 2018). Vaccine serology and self-reported infection counts are not measures of aging.

Metformin and TAME: what is actually known?

TAME — Targeting Aging with Metformin — was designed as a large randomised placebo-controlled trial in older adults without diabetes, built around a composite of new age-related diseases. Public descriptions name cardiovascular disease, cancer, dementia and death, and about 3,000 people over about six years.

The honest state of it: no ClinicalTrials.gov record for TAME appeared in our search, so the registered endpoints could not be checked; the American Federation for Aging Research's 2025 report still lists TAME as a programme, not a trial with outcomes; and 2026 web summaries cite registry numbers that did not resolve to TAME. The planned size above therefore comes from public accounts, not a registry record, and there is no participant-level result. Any text saying TAME showed that metformin slows aging describes something unpublished.

Metformin is approved worldwide for type 2 diabetes, and that licence is about glucose. Small studies do measure aging-related markers on it — autophagy markers in prediabetes (NCT03309007), a pilot of senescence and immune markers (NCT06459310) — but markers are not disability, dementia or death. And the observational story that metformin users live longer is confounded by why it was prescribed.

Senolytics: what did the trials actually measure?

Dasatinib plus quercetin is the combination behind the word senolytic. The trials with published results are below, all on an intermittent schedule, and each endpoint is the point.

• Bone metabolism in postmenopausal women, 2024. Phase 2, randomised, controlled, 60 participants analysed, 20 weeks. The primary endpoint — the bone-resorption marker CTx — did not differ between groups (P = 0.611). The bone-formation marker rose at weeks 2 and 4 and was no different from control by week 20. This is the largest randomised trial of this combination, and its primary endpoint is null.

• Diabetic kidney disease, 2019. Open-label, 9 adults (mean age about 69), three days of dosing. Eleven days later, markers of senescent cells in fat tissue were lower (p16, p21, senescence-associated β-galactosidase) — a tissue stain, not kidney function.

• Pulmonary fibrosis, 2019 and 2023. An open-label pilot in 14 people over three weeks with no placebo, then a randomised pilot in 12 people against placebo. Both were built for side effects and feasibility, not efficacy: all 108 planned doses were taken, no serious adverse event was attributed to the combination, and the placebo group reported fewer non-serious events (22 versus 65). Neither claims the drug treats the disease. The open-label pilot did report significantly improved 6-minute walk distance, gait speed and chair-stand time (p < .05), though the abstract gives no numeric value for the change, and pulmonary function and self-reported health were unchanged; its primary endpoints were retention and completeness of assessments, and one serious adverse event was recorded. In the randomised pilot against placebo those same functional measures did not differ meaningfully between groups — the gain from the open-label pilot did not reproduce under placebo control.

• Early Alzheimer's disease, 2023. Open-label phase 1, 5 people, mean age about 76, 12 weeks. Dasatinib reached cerebrospinal fluid in 4 of 5; quercetin did not. Cognitive and imaging endpoints did not change significantly, and spinal-fluid IL-6 and GFAP rose.

• Fibrotic MASH, 1 October 2026. Phase 2, double-blind, single centre, 31 people (median age 56, 76% men, 58% with type 2 diabetes), randomised 1:1, about 21 weeks. Primary endpoint: at least one stage of fibrosis improvement on paired biopsies without worsening MASH — 8 of 17 (47%) versus 1 of 14 (7%), P = 0.02; MASH resolution 53% versus 7%. No confidence interval in the abstract. Adverse events 82% versus 43%, self-limited.

The MASH trial is the strongest result here: liver histology in 31 people at one centre, not repeated. Dasatinib is an approved leukaemia drug and carries its risks; it is not approved for MASH, fibrosis, Alzheimer's or aging, and quercetin here is not an approved medicine.

Klotho: is there any human evidence?

The klotho evidence that holds up as a study is genetic, and nobody in it was given a drug. In three cohorts of older adults without dementia, carriers of one copy of the KL-VS variant of KLOTHO scored higher on cognitive tests (Dubal and colleagues, Cell Reports, 2014). A later sample of 1,812 adults aged 55 to 87 did not find better scores in heterozygotes (Scientific Reports, 2021 — cited by journal and year, because its identifier was not verified in our check).

Two interventional studies are registered, both from one sponsor, open-label, with no placebo and no results posted: an injectable klotho plasmid (NCT07216781, phase 1 in healthy adults, with serum α-klotho among the primary measures) and a klotho-plus-follistatin plasmid (NCT07285629, early phase 1, single group). The registry note on the first says the injection is given outside the United States and is not an FDA-regulated drug.

So there is nothing to quote: no percent change, no cognitive difference, no safety table.

What none of this shows

No drug above has shown longer life or fewer diseases in people. PEARL's primary endpoint was null, the everolimus endpoints immune, the senolytic endpoints tissue markers, feasibility or liver histology in 31 people; TAME has no result and klotho no controlled human outcome.

Approved for something else is not approved for aging. Sirolimus is licensed in transplant rejection and lymphangioleiomyomatosis, everolimus in transplant and oncology, metformin in type 2 diabetes, dasatinib in specific leukaemias — each with its own risks.

Secondary, completer-based findings are hypotheses, which is what every positive result in PEARL is.

A small significant result can be chance. The MASH finding, at 31 people with no confidence interval and no replication, is a reason to run a larger trial, not to act.

Markers are not outcomes, and none of this ran for a lifetime. A senescence stain, an antibody titre or a serum klotho level is a step in an argument; the longest exposure above is weeks to a year.

What to do with this now

The practical value of this field today is a filter, not a prescription. When something is offered as an anti-aging treatment, six questions settle most of it: what phase, how many people, was there a placebo, what was the pre-specified primary endpoint, was the result published or only announced, and is it approved for this use? Open-label, no placebo, no posted results, no approval is the profile of the klotho plasmid studies above — and of much sold here.

Off-label use of an approved drug for aging belongs to a physician who knows your history and your medicines; the trials above do not support it as a longevity intervention. What is measurable today is ordinary: blood pressure, lipids, glucose, body composition, function — quantities with validated endpoints.

Sources

• Farr JN et al. Effects of intermittent senolytic therapy on bone metabolism in postmenopausal women: a phase 2 randomized controlled trial. Nat Med. 2024. PMID 38956196 · doi:10.1038/s41591-024-03096-2 · NCT04313634

• Moel M et al. PEARL: rapamycin, safety and healthspan after one year. Aging (Albany NY). 2025. PMID 40188830 · DOI 10.18632/aging.206235 · NCT04488601

• Mannick et al. mTOR inhibition and immune function in older adults. Sci Transl Med. 2014. PMID 25540326 · DOI 10.1126/scitranslmed.3009892

• Mannick et al. Low-dose TORC1 inhibition, immune function and infections in older adults. Sci Transl Med. 2018. PMID 29997249 · DOI 10.1126/scitranslmed.aaq1564

• Hickson et al. Dasatinib plus quercetin and senescent cells in diabetic kidney disease. EBioMedicine. 2019. PMID 31542391 · DOI 10.1016/j.ebiom.2019.08.069 · NCT02848131

• Justice et al. Dasatinib plus quercetin in idiopathic pulmonary fibrosis, first-in-human open-label pilot. EBioMedicine. 2019. PMID 30616998 · DOI 10.1016/j.ebiom.2018.12.052

• Dasatinib plus quercetin in idiopathic pulmonary fibrosis, randomised pilot. EBioMedicine. 2023;90:104481. NCT02874989

• Gonzales MM et al. SToMP-AD: dasatinib plus quercetin in early Alzheimer's disease, phase 1. 2023. PMID 37679434 · NCT04063124

• Dasatinib plus quercetin in fibrotic MASH, phase 2. Nature Metabolism. 2026. DOI 10.1038/s42255-026-01643-4 · NCT05506488. A PubMed identifier for this paper appeared only in an import record and was not verified, so it is not linked here.

• Dubal et al. Life extension factor klotho and cognition. Cell Reports. 2014. PMC4176932

• Population sample of 1,812 adults aged 55–87 finding no cognitive advantage in KL-VS heterozygotes. Scientific Reports. 2021. Cited by journal and year: the identifier was not verified in our source check, so no link is given.

• Injectable klotho plasmid, phase 1, open-label, no results posted. NCT07216781

• Klotho plus follistatin plasmid, early phase 1, open-label, no results posted. NCT07285629

• Metformin and autophagy markers in prediabetes. NCT03309007

• Metformin pilot of senescence and immune markers. NCT06459310

• TAME (Targeting Aging with Metformin): no ClinicalTrials.gov record was found in our search, and the American Federation for Aging Research's 2025 report lists it as a programme rather than a trial with outcomes. No link is given because no primary record was verified.

Informational material. It does not replace a consultation with a physician and is not a treatment recommendation.