Cordyceps and medications.
Cordyceps is in the Distil supplement database, evidence Grade B/C. The page below lists every medication we have explicitly assessed it against.
Cordyceps, usually sold as Cordyceps militaris extract, is a medicinal fungus marketed for athletic performance and energy. We do not recommend it for any goal, and it is worth explaining why, because the headline result is quoted almost everywhere. The trial usually cited as showing a VO2max improvement did not test cordyceps on its own: the supplement was a six-mushroom blend, so no cordyceps dose can be attributed, and its full 28-person randomised comparison found no significant effect on any of its six measures. The one positive figure comes from the ten people who carried on to three weeks. A second supportive study combined cordyceps with rhodiola, so it cannot separate the two. The only trial that tested a single cordyceps product at a dose in the usual range, in 22 trained cyclists over five weeks, found nothing at all: no change in VO2peak, ventilatory threshold or time trial. For energy, libido, immunity and longevity there is no trial evidence in our database of any kind, and mitochondrial ATP production is a mechanism rather than a measured outcome. If a placebo-controlled trial of Cordyceps militaris alone is published, we will revisit it. Typical dosing, if you take it anyway, is 1,000 to 3,000mg a day. On interactions, cordyceps modulates the immune system, so it should be excluded in autoimmune conditions, is not appropriate in HIV or AIDS, and it carries a potential mild effect with anticoagulants. Organ transplant is a different picture: cordyceps has actually been studied as a supervised add-on to anti-rejection medication, where it can change how much of those drugs you need, so it should only be used with your transplant team and never added on your own to a settled immunosuppressant dose. Taken late it can disturb sleep. If you do use it, the militaris form is the better choice, because sinensis has supply-chain and standardisation problems, but our position is that the endurance case has not been made.
Below are the 12 documented pairs we have explicitly assessed for Cordyceps: 12 amber. The pairs cluster around 2 mechanisms: Additive anticoagulation and Immunosuppression caution. Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not listed here is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by medication, and the missing-item form at the bottom of the page routes any uncatalogued medication 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 anticoagulation
Amber Does Cordyceps interact with Acenocoumarol?
Cordyceps may add to acenocoumarol's blood-thinning effect through a mild anti-clotting action of its own. This is based on laboratory work on human platelets rather than studies in people taking acenocoumarol, so the real-world size of the effect is unknown. If you take acenocoumarol, mention cordyceps to your anticoagulation clinic and ask whether an INR check is worth doing after you start.
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 Cordyceps interact with Warfarin sodium?
Cordyceps may add to warfarin's blood-thinning effect through a mild antiplatelet action of its own. This is based on laboratory work on human platelets rather than studies in people taking warfarin, so the real-world size of the effect is unknown. If you take warfarin, mention cordyceps to your anticoagulation clinic and ask whether an INR check is worth doing after you start.
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 Cordyceps interact with Ciclosporin?
Cordyceps is often taken to support the immune system, but in transplant studies it actually adds to immune suppression rather than working against it, and patients were given less ciclosporin and ran lower levels without more rejection. Because ciclosporin has a narrow safe range, starting or stopping cordyceps on your own could shift your levels without anyone watching. Do not change your cordyceps use 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 Cordyceps interact with Efavirenz?
Cordyceps is sold as an immune supplement, but the human trials behind it were run in transplant patients where it acted alongside immune-suppressing medicines rather than against them, so what it does to an immune system already being managed for HIV has never been studied and it belongs with your HIV team before you start it. Efavirenz is handled by a different liver pathway from the protease inhibitors and is taken without a booster, and our curated interaction database records no evidence that cordyceps touches either that pathway or the one the protease inhibitors use. The reason for care here is your immune monitoring rather than your drug levels.
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 Cordyceps interact with Everolimus?
Cordyceps is taken to support the immune system, but in transplant studies it adds to immune suppression rather than opposing it. Everolimus is a narrow-range transplant and cancer medicine, so taking cordyceps on your own could shift the balance without anyone watching. Do not start or stop cordyceps without the specialist who manages your everolimus.
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 Cordyceps interact with Sirolimus?
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.
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 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.
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. Use the checker below to surface any medication, and submit a missing item if you take something we have not catalogued.
No affiliates. No commission. We earn nothing on what you buy.
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 methodologyA 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 founder pricing while Distil is new, or returning within 6 months · £79 standard.
Something 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.