Supplements and Sirolimus.
Sirolimus, sold under the brand name Rapamune, is an mTOR inhibitor used as a post-transplant immunosuppressant. The therapeutic window is narrow and CYP3A4-driven.
Sirolimus is an mTOR inhibitor immunosuppressant. The class includes sirolimus and everolimus. Mechanism differs from calcineurin inhibitors, but the therapeutic window is just as narrow and the CYP3A4 dependence is just as strong. Trough plasma levels are monitored after transplantation, or in the specific oncology indications. The same CYP3A4-active supplement exclusion list applies. Curcumin, quercetin at higher doses, resveratrol, schisandra, St John's Wort, and bergamot extract all change plasma mTOR inhibitor levels in measurable ways. Grapefruit and Seville orange are textbook exclusions and are listed in the BNF and product literature. Immune-stimulating supplements (echinacea, andrographis, elderberry, cordyceps, astragalus) work against the drug and are excluded too. Use in cancer overlaps further with the active cancer context flag in our checker, since several supplements that are otherwise lower risk become exclusions during active oncology care.
Below are the 11 documented pairs we have explicitly assessed against Sirolimus in the Distil database: 6 red and 5 amber. The pairs cluster around 3 mechanisms: CYP3A4 inhibition, Immunosuppression caution, and Nrf2 + CYP modulation. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
CYP3A4 inhibition
Berberine can slow how the body clears sirolimus, which may push sirolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Bergamot is grapefruit-family citrus and can raise sirolimus blood levels by slowing its clearance. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Curcumin can slow how the body clears sirolimus, which may push sirolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Quercetin can slow how the body clears sirolimus, which may push sirolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Resveratrol can slow how the body clears sirolimus, which may push sirolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Schisandra slows how the body clears sirolimus and can roughly double sirolimus blood levels, which risks toxicity. Do not combine the two outside direct transplant-team supervision.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Immunosuppression caution
If you take a medicine that suppresses your immune system, check with your specialist before starting any probiotic. The pasteurised (non-living) form used here lowers the usual concern, but immune data are incomplete, so a quick word with your team is the safe route.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Bifidobacterium longum 1714 is a live bacterium, and for most people it is safe. But sirolimus strongly dampens the immune system, usually after a transplant, and in people whose defences are this weakened there have been rare cases of a probiotic organism getting into the bloodstream and causing an infection. If you take sirolimus, check with your specialist team before starting this strain, and avoid it if you are seriously unwell in hospital or have a central line or drip.
Cordyceps is taken to support the immune system, but in transplant studies it adds to immune suppression rather than opposing it. Sirolimus is a narrow-range transplant medicine, so taking cordyceps on your own could shift the balance without anyone watching. Do not start or stop cordyceps without your transplant team.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Probiotics are live bacteria or yeast, and for most people they are safe. But sirolimus strongly dampens the immune system, usually after a transplant, and in people whose defences are this weakened there have been rare cases of the probiotic organism getting into the bloodstream and causing an infection. If you take sirolimus, check with your specialist team before starting a probiotic, and avoid them if you are seriously unwell in hospital or have a central line or drip.
Nrf2 + CYP modulation
Sulforaphane activates a body-wide antioxidant pathway (Nrf2) that can also subtly affect liver enzymes responsible for clearing sirolimus. The effect at supplement doses is uncertain, but for a narrow-window drug like sirolimus the cautious path is to discuss with your transplant team before starting.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologyWant this checked across everything you take?
This page checks the pairs you enter. The personalised Distil report goes further:
- the same graded, cited interaction check across your whole stack, not just the pairs you thought to type in
- where your current routine may be leaving you short of your goals
- the evidence-backed compounds worth adding, and the ones worth dropping
It's a paid report: £79, or £49 for the first 25 customers. The interactions check is one section of it, and you can read a real one in full before you buy.
See a real sample reportSomething missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.