Does rapamycin help people live longer in good health?
Rapamycin demonstrably extends the lifespan of mice and other animals, but whether the same holds true for humans has not yet been supported by large clinical studies. Do not use it without medical supervision: side effects are real and many organ systems have barely been studied in humans.
In mice, rapamycin is the first drug to have demonstrably extended maximum lifespan in both sexes. This effect has been reproduced in multiple independent studies, including in yeast, worms and flies. One caveat is that the longer lifespan seen in mice is probably due in large part to rapamycin suppressing cancer, which is the leading cause of death in the most commonly used mouse strains. Whether the drug actually slows the ageing process itself is therefore less certain. Beyond lifespan, rapamycin also improved age-related cognitive decline in mice.
How rapamycin achieves this has been partly unravelled. The drug raises the amount of spermidine inside cells. Spermidine is a naturally occurring substance that then activates cellular housekeeping: cells clear out damaged components. In animal models, the anti-ageing effects disappear when this pathway is blocked.
In humans the picture is considerably more cautious. A systematic review of 19 studies found beneficial effects on the immune system, the cardiovascular system and the skin. No demonstrable effect was found for muscles, the nervous system or the hormonal system. Effects on the kidneys, lungs, digestive system and reproductive system have not yet been studied at all in humans. Large, long-running trials are still lacking.
Safety deserves attention. In people who already had age-related diseases, more infections and unfavourable blood lipid levels were reported. A survey study of 333 people taking rapamycin outside of official use provided initial indications that it may be relatively safe in otherwise healthy adults, but these are self-reported data without a control group. A small randomised study (36 participants, 19 drop-outs) found that rapamycin cream applied to the skin lowered ageing markers and made the skin look better; the results are of limited reliability given the small size and high drop-out rate.
Animal evidence is robust (multiple independent studies, multiple species). Human data are limited to a systematic review of 19 studies without large RCTs, a small RCT on skin cream, and observational survey data. No long-term anti-ageing trials in humans are available.
What do we know about rapamycin as an anti-ageing agent in humans?
Rapamycin shows early positive signals in humans for immune function and skin, but long-term safety is unknown and side effects such as infections and unfavourable blood lipids are a real risk. Use outside a clinical trial is premature.
Will a doctor prescribe rapamycin?
Most doctors will not prescribe rapamycin to healthy people to slow ageing, simply because the evidence for doing so is still lacking. For certain rare conditions a specialist may consider it off-label, but always with a careful weighing of the risks.
Does metformin help you live a longer, healthier life?
For people with type 2 diabetes, metformin has real health benefits, but whether it also keeps healthy people fit for longer is something we do not yet know. Wait for the results of the large ongoing studies before considering it as an anti-aging agent, and always discuss its use with your doctor.
Does rapamycin put a burden on the liver?
Rapamycin does not demonstrably damage the liver directly, but does increase the risk of a blood clot in the hepatic artery and has known side effects elsewhere. Use this drug only under medical supervision.
Does rapamycin improve skin aging?
Topical rapamycin showed promising signs for skin ageing in a small study, but the evidence is still too thin to justify self-application.
Can rapamycin reverse or prevent grey hair?
Rapamycin shows interesting effects on pigmentation in the lab and in a rare hereditary disease, but there is no evidence whatsoever that it reverses or prevents grey hair in healthy people.