Supplements and anticoagulants.
Anticoagulants sit in a narrow therapeutic window. Push too far in either direction and the consequence is either a bleed or a clot. Warfarin is the most interaction-prone, but the direct oral anticoagulants (apixaban, rivaroxaban, dabigatran, edoxaban) also have documented supplement interactions.
Several supplements have INR-shifting evidence: curcumin, CoQ10, garlic extract, ginger, ginkgo, and high-dose fish oil push toward more anticoagulation. Vitamin K2 pulls in the opposite direction: even at ordinary supplement doses it can reduce warfarin's effect, so do not start it on warfarin without your anticoagulation clinic. St John’s Wort reduces warfarin levels via CYP induction and is a hard exclusion. Most of these are manageable with INR monitoring at initiation; we flag the ones that are not.
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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.