Vol. I · No. 33
Thursday, August 13, 2026
Issue: Summer · 2026
Established · MMXXVI
— The evidence base for longevity medicine —
Indexed by PubMed · CTG · Cochrane
Editorial team · geroevidence.com
Subscription · app.geroevidence.com

The PEARL trial explained: rapamycin, immune function, and what the 2024 results mean

The PEARL trial is the most important published human trial of rapamycin for aging. A detailed breakdown of the design, results, and what they do and do not establish.

By Geroevidence editorial team·Published 19 July 2026·Category clinical trials·12 min read
§ Overview

The PEARL trial is the most important published human trial of rapamycin for aging. A detailed breakdown of the design, results, and what they do and do not establish.

Evidence tier: Moderate. Drug class: mTOR inhibitor. This profile synthesizes the published human trial evidence. The full profile with all indexed papers, active trial alerts, and tier history is available to subscribers.

§ Key human evidence
RCT
PEARL — Aging Cell, 2023
n=228
Healthy adults 50–85 years. Sirolimus (rapamycin) 5mg weekly versus placebo for 12 months. Primary endpoint: influenza vaccine immune response. Rapamycin improved vaccine response by 20% at the 5mg/week dose. Exploratory endpoints: reduced respiratory infections, improved immune aging markers. Well-designed double-blind placebo-controlled trial — the highest quality rapamycin human data to date.
Observational
AgelessRx physician survey, 2022
n=333 patients
Retrospective survey of physicians prescribing rapamycin off-label. Majority reported patient-reported improvements in energy, cognition, and exercise recovery. No control group. Self-reported outcomes. Significant selection bias. Cited frequently in longevity medicine circles but far weaker evidence than the PEARL RCT.
Animal / ITP
ITP — Journal of Gerontology, 2009
n=Multi-site mouse studies
Rapamycin is the single most replicated lifespan-extending intervention in the ITP program. Median lifespan extension of 9–14% in male and female mice, with remarkable consistency across all three ITP sites. Effect observed even when supplementation began at equivalent of age 60 in humans. Strongest animal longevity data for any intervention in the program.
§ The honest clinical position

Every Geroevidence profile ends with an honest assessment of what the evidence supports and what it does not. This intervention is rated Moderate based on the published human trial evidence indexed above.

The full honest clinical assessment — including evidence tier rationale, key limitations, and what trials would be needed to upgrade the tier — is in the subscriber profile. The summary: the mechanistic basis is coherent and human trial data is available; the specific clinical applications and limitations are detailed in the full profile.

This information is provided for educational reference only and does not constitute medical advice or a treatment recommendation.

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