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.
Rapamycin (also known as sirolimus) has no strong evidence of direct liver damage. In an observational series of 56 liver transplant patients who received rapamycin together with a low dose of the rejection-suppressing agent tacrolimus, liver and patient survival remained high (91% and 93% respectively after nearly two years). No specific liver-toxic effects were reported.
There is, however, one liver-related complication associated with rapamycin: blockage of the artery supplying the liver (hepatic artery thrombosis). In the same observational series, 1 of the 56 patients developed this. For that reason, the US Food and Drug Administration (FDA) has not approved rapamycin as an mTOR inhibitor for liver transplantation; the related drug everolimus has been approved.
The side effects that rapamycin measurably increases are found elsewhere in the body. Chronic use can lead to glucose intolerance, insulin resistance and even type 2 diabetes. In combination with full doses of cyclosporine, rapamycin also amplifies kidney toxicity and raises blood lipids (hyperlipidaemia). Rarer but serious are lung problems, including an inflammatory lung condition (interstitial pneumonitis).
Reviews mention 'possible liver effects' as a point of attention in the side-effect profile of rapamycin, but do not quantify this or provide a mechanistic explanation. That makes it difficult to estimate the true liver risk. Furthermore, all available evidence comes from observational research and reviews in transplant patients, not from controlled studies in healthy individuals or in people using rapamycin as a longevity supplement.
All sources are reviews or non-indexed observational series in transplant medicine. No RCTs or meta-analyses are available. Findings are not directly transferable to the use of low-dose rapamycin outside the transplant context.
Does rapamycin help people live longer in good health?
Rapamycin works in mice, but whether it also leads to a longer and healthier life in humans has not yet been demonstrated. Side effects are real, long-term data in healthy people are absent, and use outside a clinical context cannot currently be justified.
Can anyone take rapamycin?
Rapamycin is a powerful drug with serious side effects, including reduced immune function and blood sugar disturbances, and is not suitable for independent use outside medical supervision.
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 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.