Low-dose rapamycin improves muscle mass and well being in ageing adults
A research team has conducted a clinical trial to determine whether low-dose, intermittent rapamycin could safely improve healthspan in older adults. The findings suggest rapamycin may offer measurable benefits for physical function and overall well being, reinforcing its potential as a safe intervention to support healthy ageing.
Ageing remains the leading cause of chronic conditions such as heart disease, diabetes, and dementia. While medical advances have extended lifespan, many people still experience declining health and reduced mobility in later years.
This growing gap between lifespan and healthspan has driven interest in therapies that target ageing itself. Rapamycin, an FDA-approved drug originally used in transplant medicine, has drawn attention for its ability to influence ageing-related pathways in animal studies. Until recently, its safety and benefits in healthy human populations were largely unknown.
The PEARL trial is the longest study so far to explore rapamycin’s use for longevity in healthy ageing adults.
Researchers, led by first author Mauricio Moel and corresponding author Stefanie L. Morgan from AgelessRx, followed 114 participants aged 50 to 85 over 48 weeks in a randomised, double-blind, placebo-controlled design.
Participants received either a placebo or 5 mg or 10 mg of compounded rapamycin once per week. The study’s primary goal was to measure changes in visceral fat, while secondary outcomes included lean muscle mass, blood markers, and quality-of-life assessments.
The trial found that low-dose rapamycin was safe and well-tolerated, with serious side effects reported at similar rates across all groups. The most frequent minor issue among rapamycin users was mild gastrointestinal discomfort. While no significant reductions in visceral fat were observed, women taking 10 mg of rapamycin showed significant gains in lean muscle and reported reduced pain.
In addition, participants taking 5 mg weekly reported improvements in emotional well-being and general health, as measured by validated surveys.
“Our findings provide evidence that these rapamycin regimens are well tolerated with minimal adverse effects when administered for at least one year within normative ageing individuals,” the authors write.
Researchers noted some limitations, including the relatively small and health-conscious participant group, which may have limited the ability to detect larger effects. The compounded form of rapamycin used also had lower absorption than commercial versions, possibly reducing its impact.
Overall, the PEARL trial provides early clinical evidence that low-dose rapamycin may help support physical and emotional well-being in older adults. Further studies with larger and more diverse populations will be essential to confirm the study results and refine dosing strategies for broader application.
