What the data show
Rapamycin is an approved medicine that stops the body rejecting a transplanted kidney, and it treats a rare lung disease. Using it for ageing is not an approved use, and no study has measured how long people live.
Studies in people are small and short:
- PEARL. In a 48-week study of rapamycin taken once a week, made by a pharmacy, the main target, fat around the organs in the belly, did not change. Body mass without fat and pain improved in women on 10 mg, and some wellbeing scores improved at 5 mg [1]. A company selling rapamycin prescriptions paid for it, and many extra comparisons were run.
- RAPA-EX-01. In 40 inactive adults aged 65 to 85, sirolimus, the medicine name for rapamycin, taken once a week for 13 weeks did not add to training gains, and extra analyses favoured placebo. Side effects were more common, 99 against 63, including one pneumonia that may have been linked to the drug [2].
- Early study in older adults. In 25 adults aged 70 to 95 on 1 mg daily, memory, thinking and physical performance did not change, and red blood cell measures fell slightly [3].
Related drugs give an unclear picture. Everolimus improved the response to a flu vaccine by about 20% in older volunteers [4]. A later large study of another drug of this type, RTB101, did not reduce breathing illnesses in 1,024 older adults [5].
What the animal data really mean
Mouse data are the main reason for interest: given from 600 days of age, rapamycin extended life at three independent sites, by 14% in females and 9% in males, counted up to the death of 90% of the animals [6]. Repeating a result like this across sites and in genetically mixed mice is unusually strong.
The gap is getting from mice to people. The authors themselves note that the effect may come from delayed cancer rather than slower ageing. Pet dogs live in an environment closer to ours. A small study of 17 dogs, kept blind to which dog got what, found no heart changes at 6 or 12 months, while owners more often reported positive changes on rapamycin [7]. That shows how easily wellbeing scores mislead. One healthy dog developed very high blood fats on a low dose, which cleared after stopping [8]. The large TRIAD dog study is the one to watch.
Safety
The US label carries its strongest warning: higher risk of infection, and possible lymphoma and other cancers from a weakened immune system, at transplant doses. Known effects also include raised blood fats, mouth ulcers and slower wound healing. Long studies have not shown whether small doses with breaks avoid this in healthy people.
Sirolimus reacts with many medicines and with grapefruit juice. Its level in the blood can change a lot, so any use belongs under a doctor's care.
What we don't know
- Whether it extends healthy life in people
- Which dose and rhythm of use, if any, gives a benefit without harming immunity
- Safety over many years in healthy people
- How it affects muscle response to training
Alternatives
The best-studied ways to age well are on the longevity page.
When to see a doctor
Anyone taking sirolimus needs a doctor's care. See a doctor quickly for fever, signs of infection, mouth ulcers that do not heal, or slow wound healing. Call 112 for severe breathlessness or swelling of the face or throat. Suspected side effects can be reported to the national medicines agency, in Poland URPL.
