# mTOR

mTOR is a master growth switch inside your cells. The name stands for "mechanistic target of rapamycin," and it is an enzyme (a serine/threonine kinase) that reads the signals around it (amino acids, growth factors, how much energy the cell has) and decides whether to build proteins and grow, or slow down and recycle through autophagy. It works in two forms, mTORC1 and mTORC2. When mTORC1 stays switched on too hard for too long, it speeds up aging. Dial it down with the drug rapamycin and lifespan goes up in everything from yeast to mice, which makes mTOR one of the best-validated longevity targets we have.

## Sources

- Saxton RA, Sabatini DM. (2017). mTOR Signaling in Growth, Metabolism, and Disease. Cell. https://doi.org/10.1016/j.cell.2017.02.004
- Harrison DE, Strong R, Sharp ZD, et al.. (2009). Rapamycin fed late in life extends lifespan in genetically heterogeneous mice. Nature. https://doi.org/10.1038/nature08221

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_Canonical: https://longevity-switzerland.com/en/glossary/mtor · Part of Longevity Cities · Updated 2026-06-22_