Supplements and immunosuppressants.
Transplant immunosuppressants (tacrolimus, ciclosporin, sirolimus, everolimus) have very narrow therapeutic windows. They are metabolised by CYP3A4. Any supplement that inhibits or induces CYP3A4 shifts blood levels in a way that risks either toxicity or graft rejection. This is the highest-stakes category in our database.
Hard exclusions: curcumin, quercetin, resveratrol, schisandra, berberine, bergamot, boswellia and St John’s Wort all act on CYP3A4 and are off the table on tacrolimus, ciclosporin, sirolimus and everolimus. Potassium is off the table on ciclosporin and tacrolimus too, because both make the body hold on to potassium. Immune-active supplements (echinacea, andrographis, elderberry, astragalus, cordyceps) are also avoided in transplant patients: some may push against the deliberate immunosuppression, and cordyceps, which has been studied as an add-on to it, can change how much anti-rejection medicine you need. Anything you consider should go through the transplant team first.
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How the checker decides
Every result has a source
Each pair we have assessed is cited to a published study (PMID) or the British National Formulary, so you can read the source yourself.
Four kinds of answer
Severe, caution, no known interaction, and not yet assessed. A pair we have not assessed is never shown as clear.
- Severe
- Caution
- No known interaction
- Not yet assessed
Nothing in our data is not a clearance
When nothing in our data records a problem with a pair, the result says no known interaction at typical doses, which is not a clearance: your pharmacist or GP can check the pair against your full medical history.
A full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
£49 until 30 June 2027 · £79 from 1 July 2027.
Something missing?
If a supplement or medication you take isn't in our autocomplete, tell us. What people flag joins the queue of what we add next.