Can you take Vitamin K2 and Warfarin together?
Not together — this combination should be avoided.
Vitamin K2 and Warfarin should not be taken together without medical supervision.
Why these two interactSources for why these two interact: Jumps to this entry in the sources and references list at the end of the page.
Vitamin K directly opposes how warfarin works, which can make the blood thinner less effective.
What to do about itSources for what to do about it: Jumps to this entry in the sources and references list at the end of the page.
Do not start vitamin K supplements on warfarin without your provider's guidance.
TimingSources for timing: Jumps to this entry in the sources and references list at the end of the page.
Separating the doses does not solve this one. The concern is the combined effect in the body, not absorption timing, so spacing them out is not a workaround.
The two items in this pair
Warfarin
- Category:
- medication
- Typical timing:
- evening
- With food:
- either
- Half-life:
- 20 h
Check your whole routine, not just this pair
One pair rarely tells the whole story. DoseRoutine checks every combination in your stack at once — supplements, TRT, peptides, GLP-1s and prescriptions — and schedules the doses so timing conflicts like this one are handled automatically.
Frequently asked
Sources cited on this page
Specific documents referenced by the numbered markers above.
- Coumadin (warfarin sodium) — FDA prescribing information(opens in a new tab)DailyMed — U.S. National Library of Medicine · dailymed.nlm.nih.gov/dailymed/drugInfo.cfm
- The effect of low-dose oral vitamin K supplementation on INR stability in patients receiving warfarin(opens in a new tab)PubMed — National Library of Medicine · pubmed.ncbi.nlm.nih.gov/27346552/
- Vitamin K — Fact Sheet for Health Professionals(opens in a new tab)NIH Office of Dietary Supplements · ods.od.nih.gov/factsheets/VitaminK-HealthProfessional/
Verify at
This assessment is mechanism-based. These publisher search links let you check it against the current evidence — they are not citations, so they are not numbered.
- PubMed: Vitamin K2 + Warfarin(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed label: Vitamin K2(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- DailyMed label: Warfarin(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
Related combinations
Educational information only, not medical advice. DoseRoutine does not diagnose or treat. Talk to your prescriber before starting, stopping or combining anything — especially if you take prescription medication or are pregnant or breastfeeding.