EvidenceCLimitedStudies in people with real weaknesses: small, short or conflicting trials, or observational studies only.
In small, short trials, low-dose rapamycin caused few serious problems in healthy adults. Long-term safety for healthy people is unknown, and the drug is approved only for transplant and certain diseases.
Who it's for
No healthy group has a proven benefit; it is approved only for transplant patients.
What to expect
Mostly mild side effects over weeks to a year; benefits are unproven.
Watch out for
Higher infection risk, mouth sores, and changes in blood counts and cholesterol.
Weekly rapamycin did not clearly change exercise gains
Each dot shows the difference in chair stands versus placebo, with a line for its likely range.
← WorseBetter →
No difference
All participants−2.13 (−4.61 to 0.34)No clear difference
Those with complete data−2.46 (−4.87 to −0.06)Probably worse
Those who followed the plan−3.44 (−5.86 to −0.99)Clear worsening
−6−4−20
chair stands in 30 seconds vs. placebo
Weekly rapamycin did not clearly change exercise gains
A 48-week trial in healthy adults gave placebo A dummy treatment that looks like the real one, so people can't tell which they got. (a dummy pill), 5 mg or 10 mg of compounded rapamycin weekly. Side effects and serious side effects were similar across groups, and blood tests stayed in normal ranges3Randomized trial · 2025Influence of rapamycin on safety and healthspan metrics after one year: PEARL trial results.Low-dose, intermittent rapamycin administration over 48 weeks is relatively safe in healthy, normative-aging adults, and was associated with significant improvements in lean tissue mass and pain in women. Future work will evaluate benefits of a broader range of rapamycin doses on healthspan metrics for longevity, and…Aging (Albany NY). The trial is described as the largest and longest of its kind3Randomized trial · 2025Influence of rapamycin on safety and healthspan metrics after one year: PEARL trial results.Low-dose, intermittent rapamycin administration over 48 weeks is relatively safe in healthy, normative-aging adults, and was associated with significant improvements in lean tissue mass and pain in women. Future work will evaluate benefits of a broader range of rapamycin doses on healthspan metrics for longevity, and…Aging (Albany NY).
A review of 19 studies found no serious side effects attributed to rapamycin or related drugs in healthy people. In people with age-related diseases, infections and levels of total cholesterol, LDL cholesterol and triglycerides rose1Systematic review · 2024Targeting ageing with rapamycin and its derivatives in humans: a systematic review.No serious adverse events attributed to rapamycin and its derivatives were reported in healthy individuals; however, there were increased numbers of infections and increases in total cholesterol, LDL cholesterol, and triglycerides in individuals with ageing-related diseases. Future studies should assess the remaining…Lancet Healthy Longev.
A trial of 40 sedentary adults aged 65 to 85 gave 6 mg of sirolimus (rapamycin) weekly for 13 weeks. Side effects were reported by 85% in both groups, but there were more events with sirolimus (99 versus 63). That gap could be down to chance. Drug-related events were more frequent (35% versus 15%), and one serious pneumonia case was possibly drug-related5Randomized trial · 2026 · 40 peopleExercise and Weekly Sirolimus (Rapamycin) in Older Adults: RAPA-EX-01 Randomised, Double-Blind, Placebo-Controlled Trial.In this exploratory trial, once-weekly sirolimus (rapamycin) 6 mg did not enhance, and in sensitivity analyses, it may have modestly attenuated short-term functional improvements from a home exercise programme in older adults. The regimen also increased the burden of minor adverse events and may have contributed to…J Cachexia Sarcopenia Muscle.
A pilot trial of 25 healthy adults aged 70 to 95 gave 1 mg daily or placebo. Side effects were facial rash, mouth sores and stomach problems. Red blood cell measures, including hemoglobin, fell, though without clinical effects over about 8 weeks. Blood sugar and insulin response did not change4Randomized trial · 2018 · 2 peopleA randomized control trial to establish the feasibility and safety of rapamycin treatment in an older human cohort: Immunological, physical performance, and cognitive effects.Importantly, the OGTTs revealed no RAPA-induced change in blood glucose concentration, insulin secretion, and insulin sensitivity. Thus, based on the results of our pilot study, it appears that short-term RAPA treatment can be used safely in older persons who are otherwise healthy; a trial with a larger sample size…Exp Gerontol.
Trials of related drugs (everolimus-type mTOR blockers) in older adults at low doses were well tolerated over 6 weeks, and infections reported over a year fell in one trial2Randomized trial · 2018 · 264 peopleTORC1 inhibition enhances immune function and reduces infections in the elderly.In addition, we observed an up-regulation of antiviral gene expression and an improvement in the response to influenza vaccination in this treatment group. Thus, selective TORC1 inhibition has the potential to improve immune function and reduce infections in the elderly.Sci Transl Med,6Randomized trial · 2014mTOR inhibition improves immune function in the elderly.RAD001 also reduced the percentage of CD4 and CD8 T lymphocytes expressing the programmed death-1 (PD-1) receptor, which inhibits T cell signaling and is more highly expressed with age. These results raise the possibility that mTOR inhibition may have beneficial effects on immunosenescence in the elderly.Sci Transl Med. Those results come from different drugs, so they may not apply to rapamycin itself.
Key studies
Study
Who
What it found
Trial, 20253Randomized trial · 2025Influence of rapamycin on safety and healthspan metrics after one year: PEARL trial results.Low-dose, intermittent rapamycin administration over 48 weeks is relatively safe in healthy, normative-aging adults, and was associated with significant improvements in lean tissue mass and pain in women. Future work will evaluate benefits of a broader range of rapamycin doses on healthspan metrics for longevity, and…Aging (Albany NY)
Healthy adults, 48 weeks
Side effects similar to placebo; blood tests normal
Review of 19 studies, 20241Systematic review · 2024Targeting ageing with rapamycin and its derivatives in humans: a systematic review.No serious adverse events attributed to rapamycin and its derivatives were reported in healthy individuals; however, there were increased numbers of infections and increases in total cholesterol, LDL cholesterol, and triglycerides in individuals with ageing-related diseases. Future studies should assess the remaining…Lancet Healthy Longev
Healthy and diseased adults
No serious side effects in healthy people
Trial of 40 people, 20265Randomized trial · 2026 · 40 peopleExercise and Weekly Sirolimus (Rapamycin) in Older Adults: RAPA-EX-01 Randomised, Double-Blind, Placebo-Controlled Trial.In this exploratory trial, once-weekly sirolimus (rapamycin) 6 mg did not enhance, and in sensitivity analyses, it may have modestly attenuated short-term functional improvements from a home exercise programme in older adults. The regimen also increased the burden of minor adverse events and may have contributed to…J Cachexia Sarcopenia Muscle
Adults 65 to 85, 13 weeks
More minor side effects; one possible serious infection
Trial of 25 people, 20184Randomized trial · 2018 · 2 peopleA randomized control trial to establish the feasibility and safety of rapamycin treatment in an older human cohort: Immunological, physical performance, and cognitive effects.Importantly, the OGTTs revealed no RAPA-induced change in blood glucose concentration, insulin secretion, and insulin sensitivity. Thus, based on the results of our pilot study, it appears that short-term RAPA treatment can be used safely in older persons who are otherwise healthy; a trial with a larger sample size…Exp Gerontol
Healthy adults 70 to 95
Mild side effects; red blood cell measures dropped
Safety
The FDA label for sirolimus carries a boxed warning: suppressing the immune system raises susceptibility to infection and may lead to lymphoma and other cancers. It also warns of lung inflammation (interstitial lung disease), which sometimes cleared after stopping or lowering the dose11Guideline · 2024Sirolimus: FDA drug label (prescribing information)Warnings and precautions: In some cases, the ILD was reported with pulmonary hypertension (including pulmonary arterial hypertension [PAH]) as a secondary event. In some cases, the ILD has resolved upon discontinuation or dose reduction of sirolimus. The risk may be increased as the trough sirolimus concentration in…US Food and Drug Administration. These warnings come from transplant use at higher doses, and low "longevity" doses haven't been shown to carry the same risks. A review also discusses negative metabolic side effects of rapamycin10Review · 2016The Mechanistic Target of Rapamycin: The Grand ConducTOR of Metabolism and Aging.This review discusses recent developments in our understanding of how mTOR signaling is regulated by nutrients and the role of the mTOR signaling pathway in key metabolic tissues. Finally, we discuss the molecular basis for the negative metabolic side effects associated with rapamycin treatment, which may serve as…Cell Metab. A clinician decides whether a prescription drug is appropriate.
What we don't know
Whether years of use in healthy people raise infection, cancer or metabolic risks. The longest trial lasted 48 weeks.
Whether rapamycin gives any health benefit to healthy people that outweighs these risks.
Written by AI from the studies listed, without review by a clinician, and graded with the GRADE method. It can be wrong, so check the studies it cites. Education, not medical advice.