Can You Take St. John's Wort and Vitamin K Together?
No documented interaction was identified between St. John's Wort and vitamin K in the sources reviewed.
See the full St. John's Wort page and Vitamin K page for other reviewed interactions and reference information.
What the interaction means
NCCIH's St. John's Wort page names several drugs it can weaken (antidepressants, birth control, cyclosporine, anticonvulsants, heart medications, HIV drugs, cancer medications, warfarin, certain statins) -- vitamin K is not among them. MedlinePlus's vitamin K page does not mention St. John's Wort.
No documented interaction between St. John's Wort and Vitamin K was identified in the authoritative sources reviewed. This is not a guarantee that no interaction exists for every dose, formulation, or individual -- it means the sources checked did not document one.
Practical context
NCCIH's St. John's Wort page and MedlinePlus's vitamin K page were checked directly, full text, in both directions. Vitamin K is not among St. John's Wort's named CYP450/P-glycoprotein-affected drugs.
What the sources say
Last reviewed 2026-08-25
Medical information disclaimer: this information is general and educational. It does not diagnose conditions, prescribe treatment, or determine whether a combination is safe for you personally. Follow your prescription label and ask a pharmacist or clinician before starting, stopping, or combining products. Full disclaimer.
Related guides
Related interactions
- St. John's Wort and CiprofloxacinInsufficient evidence
- St. John's Wort and WarfarinUse caution
- St. John's Wort and SertralineUse caution
- St. John's Wort and Vitamin EInsufficient evidence
- St. John's Wort and PotassiumInsufficient evidence
- St. John's Wort and SpironolactoneInsufficient evidence
- St. John's Wort and OmeprazoleInsufficient evidence
- St. John's Wort and MetforminInsufficient evidence
- St. John's Wort and DoxycyclineInsufficient evidence
- St. John's Wort and CopperInsufficient evidence
- St. John's Wort and CaffeineInsufficient evidence
- St. John's Wort and Vitamin DInsufficient evidence
- St. John's Wort and CreatineInsufficient evidence
- St. John's Wort and Vitamin CInsufficient evidence
- St. John's Wort and CalciumInsufficient evidence
- St. John's Wort and IronInsufficient evidence
- St. John's Wort and MagnesiumInsufficient evidence
- St. John's Wort and Vitamin B12Insufficient evidence
- St. John's Wort and AshwagandhaInsufficient evidence
- St. John's Wort and Omega-3 / Fish OilInsufficient evidence
- St. John's Wort and ZincInsufficient evidence
- St. John's Wort and LisinoprilInsufficient evidence
- St. John's Wort and CoQ10 (Coenzyme Q10)Insufficient evidence
- St. John's Wort and Folate / Folic AcidInsufficient evidence
- St. John's Wort and AtorvastatinMonitor
- St. John's Wort and LosartanInsufficient evidence
- St. John's Wort and MelatoninInsufficient evidence
- St. John's Wort and ProbioticsInsufficient evidence
- St. John's Wort and AspirinInsufficient evidence
- St. John's Wort and AmlodipineInsufficient evidence
- St. John's Wort and LevothyroxineInsufficient evidence
- St. John's Wort and IbuprofenInsufficient evidence
- St. John's Wort and TurmericInsufficient evidence
- St. John's Wort and EscitalopramUse caution
- Vitamin K and LisinoprilInsufficient evidence
- Vitamin K and WarfarinUse caution
- Vitamin K and CiprofloxacinInsufficient evidence
- Vitamin K and CreatineInsufficient evidence
- Vitamin K and SpironolactoneInsufficient evidence
- Vitamin K and CaffeineInsufficient evidence
- Vitamin K and CopperInsufficient evidence
- Vitamin K and LevothyroxineInsufficient evidence
- Vitamin K and Vitamin B12Insufficient evidence
- Vitamin K and PotassiumInsufficient evidence
- Vitamin K and TurmericInsufficient evidence
- Vitamin K and ZincInsufficient evidence
- Vitamin K and CalciumInsufficient evidence
- Vitamin K and DoxycyclineInsufficient evidence
- Vitamin K and OmeprazoleInsufficient evidence
- Vitamin K and CoQ10 (Coenzyme Q10)Insufficient evidence
- Vitamin K and IronInsufficient evidence
- Vitamin K and MagnesiumInsufficient evidence
- Vitamin K and SertralineInsufficient evidence
- Vitamin K and MetforminInsufficient evidence
- Vitamin K and AtorvastatinInsufficient evidence
- Vitamin K and Vitamin EMonitor
- Vitamin K and AshwagandhaInsufficient evidence
- Vitamin K and Omega-3 / Fish OilInsufficient evidence
- Vitamin K and Folate / Folic AcidInsufficient evidence
- Vitamin K and LosartanInsufficient evidence
- Vitamin K and AspirinInsufficient evidence
- Vitamin K and AmlodipineInsufficient evidence
- Vitamin K and IbuprofenInsufficient evidence
- Vitamin K and EscitalopramInsufficient evidence
- Vitamin K and Vitamin CInsufficient evidence
- Vitamin K and MelatoninInsufficient evidence
- Vitamin K and Vitamin DInsufficient evidence
- Vitamin K and ProbioticsInsufficient evidence