Harrison · Nature 2009 · Multicenter controlled animal feeding study · n=?

Rapamycin fed late in life extends lifespan in genetically heterogeneous mice.

Cited 3801 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Animal intervention study (bench/animal research is CEBM Level 5).

PubMed 19587680 · doi:10.1038/nature08221 · record verified 2026-08-26

What was done

Genetically heterogeneous male and female mice were fed rapamycin (an mTOR inhibitor) or a control diet starting late in life at 600 days of age across three independent test sites to assess effects on median and maximal lifespan and disease patterns. An additional cohort received rapamycin starting at 270 days of age and was evaluated at an interim analysis near the median survival point.

What was found

Rapamycin initiated at 600 days extended median and maximal lifespan in both sexes at all three test sites. Based on the age at 90% mortality, rapamycin increased lifespan by 14% in females and 9% in males relative to controls. Disease patterns in treated mice did not differ from controls. In the separate cohort started at 270 days of age, rapamycin also increased survival in both males and females at the interim analysis.

Why it matters

This study provided the first evidence that pharmacological mTOR inhibition can extend mammalian lifespan in both sexes, even when treatment is initiated late in life.

Limits

The study was conducted entirely in mice, so findings cannot be directly extrapolated to human safety, efficacy, or longevity. The abstract does not report the total number of mice tested, specific p-values or confidence intervals, baseline life expectancies, or whether the lifespan extension was primarily driven by cancer delay versus broader retardation of aging processes.

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