Rapamycin shows limited evidence for longevity benefits in healthy adults, reveals research

A new research paper was published in Volume 17, Issue 8 of Aging-US on August 7, 2025, titled, “What is the clinical evidence to support off-label rapamycin therapy in healthy adults?”

In this study, led by Jacob M. Hands from The George Washington University School of Medicine and Health Sciences, researchers analyzed current research to determine whether low-dose rapamycin can extend healthspan or delay aging in healthy adults. While studies in animals have shown promising results, this review found no clear clinical evidence that the same benefits apply to humans. The findings point to the urgent need for larger, better-designed human trials before recommending rapamycin for off-label use to prevent aging.

Rapamycin, originally developed as a drug to suppress the immune system, has gained interest as a possible anti-aging therapy. It works by blocking a key cellular pathway called mTOR, which plays a role in growth and metabolism. In animal studies, blocking this pathway has extended lifespan. However, the translation of these results to humans remains uncertain. The current study examined clinical trials and observational studies involving healthy adults who took low doses of rapamycin or similar drugs.

“This paper has reviewed trials of low-dose mTOR inhibition therapy in human subjects.”

Some trials showed encouraging signs. For example, older adults treated with low-dose mTOR inhibitors showed stronger immune responses and fewer respiratory infections. Other studies suggested possible improvements in subjective well-being and physical performance, such as walking speed and strength. Still, none of the trials directly showed that rapamycin extends life or clearly slows the aging process.

One small study using a biological aging model (PhenoAge) suggested that users might have reduced their biological age by nearly four years, but the estimate was based on average values, not individual patient data.

There are also concerns about side effects. While short-term use seems safe, some studies reported increases in blood lipids and markers of inflammation. Research on muscle health produced contradictory findings-some studies suggest rapamycin might reduce the body’s ability to build muscle. The impact on mental health is also unclear, with a few participants reporting increased anxiety during treatment.

The researchers emphasize that rapamycin’s role in human aging is still uncertain. Off-label use is growing among longevity clinics and individuals seeking anti-aging solutions, but there is no standard dose, and long-term safety is unknown. The authors advise that off-label use should be approached with caution, including careful monitoring and full disclosure about the limited evidence.

Overall, while animal studies have demonstrated promising effects, human trials have not yet shown that rapamycin can safely or effectively slow aging or extend lifespan. More rigorous and well-controlled studies are necessary before the drug can be considered a reliable option for healthy adults interested in longevity interventions.

Reference:

Hands JM, Lustgarten MS, Frame LA, Rosen B. What is the clinical evidence to support off-label rapamycin therapy in healthy adults?. Aging (Albany NY). 2025 Aug 7; 17:2079-2088 . https://doi.org/10.18632/aging.206300