Supplements and Tacrolimus.
Tacrolimus, sold under the brand names Prograf, Advagraf, is a calcineurin inhibitor used as a post-transplant immunosuppressant. The therapeutic window is narrow and CYP3A4-substrate-driven.
Tacrolimus is a calcineurin inhibitor immunosuppressant. It is used after organ transplantation (kidney, liver, heart, lung) and in some autoimmune indications. The therapeutic window is narrow. Too little allows rejection. Too much drives nephrotoxicity, neurotoxicity, and diabetes. Trough blood levels are checked frequently in the early period after transplant, less often as the regimen stabilises. Tacrolimus is metabolised almost entirely by CYP3A4 in the gut and liver. That makes the CYP3A4-active supplement list a hard exclude in the Distil pipeline. Curcumin (even at standard supplement doses), quercetin at high doses, resveratrol, schisandra, St John's Wort, and bergamot extract all show measurable effects on calcineurin inhibitor plasma levels. Pomelo and Seville orange carry the same warning as grapefruit. Immune-stimulating supplements (echinacea, andrographis, elderberry, cordyceps, astragalus) are also excluded on the principle that they work against the drug. The transplant team is the gatekeeper for any new supplement, not the GP.
Below are the 23 documented pairs we have explicitly assessed against Tacrolimus in the Distil database: 9 red and 14 amber. The pairs cluster around 7 mechanisms: Additive hyperkalaemia (raised potassium), CYP induction, CYP3A4 inhibition, Reduced immunosuppressant level, Immune-stimulant vs immunosuppressant (precautionary), 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
Last reviewed 14 September 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Additive hyperkalaemia (raised potassium)
Red Does Potassium interact with Tacrolimus?
Tacrolimus tends to raise blood potassium by reducing how much the kidneys pass out. A potassium supplement adds more potassium on top, and together they can push potassium high enough to affect the heart rhythm, which can be dangerous. People on tacrolimus are usually under specialist or transplant follow-up with regular blood tests, so do not add a potassium supplement unless that team has specifically advised it and is checking your blood potassium.
Evidence: Well established across multiple human studies or interaction references.
CYP induction
Red Does St John's Wort interact with Tacrolimus?
St John's Wort can cause your body to clear tacrolimus too quickly, dropping its level below the protective range and raising rejection risk. Do not combine.
Evidence: Supported by human study data.
CYP3A4 inhibition
Red Does Berberine interact with Tacrolimus?
Berberine can slow how the body clears tacrolimus, which may push tacrolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Red Does Bergamot Extract (BPF / Bergavit40) interact with Tacrolimus?
Bergamot belongs to the grapefruit-family citrus group and can slow how the body clears tacrolimus, which may push tacrolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Red Does Boswellia interact with Tacrolimus?
Boswellia may slow how the body clears tacrolimus, which can push tacrolimus blood levels higher than intended. One laboratory study points the other way, toward faster clearance and levels that drift too low. Because we cannot tell which way it would go for you, we treat this as a do-not-combine pair outside direct transplant-team supervision.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Red Does Curcumin interact with Tacrolimus?
Curcumin can slow how the body clears tacrolimus, which may push tacrolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Red Does Resveratrol interact with Tacrolimus?
Resveratrol can slow how the body clears tacrolimus, which may push tacrolimus blood levels higher than intended. We treat this as a do-not-combine pair outside direct transplant-team supervision.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Red Does Schisandra interact with Tacrolimus?
Schisandra slows how the body clears tacrolimus and can raise tacrolimus blood levels several times over, which risks toxicity. Do not combine the two outside direct transplant-team supervision.
Evidence: Supported by human study data.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Reduced immunosuppressant level
Red Does Quercetin interact with Tacrolimus?
Quercetin supplements may lower tacrolimus blood levels, so if you take tacrolimus do not start quercetin without speaking to your transplant team first. The concern runs the opposite way to most supplement interactions: the risk is too little tacrolimus rather than too much, and a fall in level can let the body begin rejecting a transplant. No study has tested quercetin with tacrolimus in people or in animals, so this caution comes from what quercetin does to ciclosporin, a closely related transplant medicine, rather than from any measured effect on tacrolimus itself.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Immune-stimulant vs immunosuppressant (precautionary)
Amber Does Ashwagandha interact with Tacrolimus?
Tacrolimus works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition. Ashwagandha has been reported to do the opposite and gently stimulate the immune system. There is no proof the two clash in people, but because the stakes with a transplant or autoimmune disease are high, it is safer not to start ashwagandha while you take tacrolimus without first talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Beta-Glucan interact with Tacrolimus?
Tacrolimus works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition. Beta-glucan from mushrooms or yeast does the opposite and gently stimulates the immune system. There is no proof the two clash in people, but because the stakes with a transplant or autoimmune disease are high, it is safer not to start beta-glucan while you take tacrolimus without first talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Elderberry interact with Tacrolimus?
Tacrolimus works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition. Elderberry is taken to support the immune system and has been shown to stimulate it. There is no proof the two clash in people, but because the stakes with a transplant or autoimmune disease are high, it is safer not to start elderberry while you take tacrolimus without first talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Eleuthero interact with Tacrolimus?
Eleuthero (Siberian ginseng) is taken to stimulate the immune system, which in theory works against a medicine like tacrolimus that is meant to suppress it. This has not been tested in people taking immune-suppressing medicines, so it is a cautious flag rather than a strong warning. If you take tacrolimus after a transplant or for an autoimmune condition, check with your specialist before starting eleuthero.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Melatonin interact with Tacrolimus?
Melatonin can stimulate parts of the immune system, which in theory works against medicines like tacrolimus that are deliberately suppressing it, for example after a transplant. There is no direct study of the two together, but because the stakes are high it is best not to start melatonin without clearing it with the team that manages your tacrolimus.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Spirulina interact with Tacrolimus?
Spirulina can stimulate parts of the immune system, which in theory works against a medicine like tacrolimus that is meant to suppress it. This has not been tested in people taking immune-suppressing medicines, so it is a cautious flag rather than a strong warning. If you take tacrolimus after a transplant or for an autoimmune condition, check with your specialist before starting spirulina.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Immunosuppression caution
Amber Does Akkermansia muciniphila (pasteurised) interact with Tacrolimus?
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.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Andrographis interact with Tacrolimus?
Andrographis is taken to stimulate the immune system, which in theory works against a medicine like tacrolimus that is meant to calm it. There is also a separate concern that andrographis may slow how the body clears tacrolimus and push its blood levels up. The human evidence for both effects is thin, so for a narrow-window transplant medicine the safe route is to check with your transplant team before starting.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Astragalus interact with Tacrolimus?
Astragalus is taken to support the immune system, which is the opposite of what tacrolimus is prescribed to do, and in one reported case the tacrolimus level fell by almost half after a herbal mixture containing astragalus was added. That case involved several herbs, so it proves little on its own, but tacrolimus has a narrow safe range. Astragalus has not been studied with tacrolimus, so do not start it without talking to your transplant or specialist team, and ask whether an extra level check makes sense.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Bifidobacterium longum 1714 interact with Tacrolimus?
If you take tacrolimus, check with your specialist team before starting this strain: tacrolimus strongly dampens the immune system, usually after a transplant or for a serious autoimmune condition, 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. Avoid any probiotic, including this strain, if you are seriously unwell in hospital or have a central line or drip. Bifidobacterium longum 1714 is a live bacterium, and the evidence that probiotics are safe for most people comes from studies of people who were not significantly immunosuppressed, so on tacrolimus let your specialist team's advice decide.
Evidence: Supported by human study data.
Amber Does Cordyceps interact with Tacrolimus?
Cordyceps is often taken to support the immune system, but the human transplant studies actually show it adds to immune suppression rather than working against it, and it can change how much calcineurin-inhibitor medicine your body needs. Because tacrolimus has a narrow safe range, taking cordyceps on your own could shift your levels without anyone watching. Do not start or stop it without your transplant team, who can adjust monitoring if needed.
Evidence: Limited human data, from small studies or case reports.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Echinacea interact with Tacrolimus?
Tacrolimus works by calming the immune system down, which is what stops your body rejecting a transplant or quietens an autoimmune condition, and echinacea is taken to support the immune system, so it may work against tacrolimus. Echinacea can also change how the body clears medicines that are handled like tacrolimus: in one volunteer study it sped that clearance up in the liver while slowing it in the gut, and a second found an overall speeding-up, so the effect on your tacrolimus level could go either way. Echinacea has not been studied with tacrolimus, so do not start it without talking to your transplant or specialist team.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
Reviewer-flagged: awaiting clinical-reviewer sign-off.
Amber Does Probiotics interact with Tacrolimus?
If you take tacrolimus, check with your specialist team before starting a probiotic: tacrolimus strongly dampens the immune system, usually after a transplant or for a serious autoimmune condition, 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. Avoid any probiotic if you are seriously unwell in hospital or have a central line or drip. Probiotics are live bacteria or yeast, and the evidence that they are safe for most people comes from studies of people who were not significantly immunosuppressed, so on tacrolimus let your specialist team's advice decide.
Evidence: Supported by human study data.
Nrf2 + CYP modulation
Amber Does Sulforaphane (Broccoli Sprout Extract) interact with Tacrolimus?
Sulforaphane activates a body-wide antioxidant pathway (Nrf2) that can also subtly affect liver enzymes responsible for clearing tacrolimus. The effect at supplement doses is uncertain, but for a narrow-window drug like tacrolimus the cautious path is to discuss with your transplant team before starting.
Evidence: No direct study of this exact combination yet; the caution rests on a plausible mechanism or on reports involving a related medicine.
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.
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