Ginger may enhance anticoagulant effect
Ginger inhibits thromboxane synthetase and may potentiate warfarin. Clinical significance is moderate - less concerning than garlic or vitamin E, but still warrants monitoring.
Use ginger cautiously with warfarin. Small culinary amounts are fine.
Monitor for increased bleeding tendency
Ginger may enhance anticoagulant effect. Use ginger cautiously with warfarin. Small culinary amounts are fine.
Monitor for increased bleeding tendency
This interaction is rated “Caution” by Formulate. Ginger inhibits thromboxane synthetase and may potentiate warfarin. Clinical significance is moderate - less concerning than garlic or vitamin E, but still warrants monitoring.
Studies from our registry that mention ginger or warfarin. Each links to the primary source and the other Formulate pages citing it.
Mentions warfarin · 2025
Impact of Ginkgo biloba drug interactions on bleeding risk and coagulation profiles
Primary literature · Observational study
Ginkgo + aspirin: bleeding risk OR 1.12 (95% CI 1.07-1.18, p<0.001); abnormal coagulation OR 1.48 (95% CI 1.32-1.66, p<0.001). Ginkgo + clopidogrel: bleeding risk OR 1.10 (95% CI 1.05-1.15, p<0.001); abnormal coagulation OR 1.58 (95% CI 1.40-1.77, p<0.001). Ginkgo + warfarin: NO statistically significant correlation with bleeding or coagulation.
Mentions warfarin · 2016
Interaction Between Dietary Vitamin K Intake and Anticoagulation by Vitamin K Antagonists: Is It Really True? A Systematic Review
Violi et al. · Medicine (Baltimore)
Conflicting evidence on whether dietary vitamin K intake affects warfarin response. Some studies show inverse correlation between vitamin K intake and INR changes. Others suggest a minimum vitamin K intake is REQUIRED for stable anticoagulation. Conclusion: available evidence does NOT support the old advice to restrict dietary vitamin K when starting warfarin. Consistency of intake matters more than absolute level.
Mentions warfarin · 2015
Ginkgo and Warfarin Interaction in a Large Veterans Administration Population
Millery et al. · AMIA Annu Symp Proc
Hazard ratio for bleeding adverse event with concurrent ginkgo + warfarin: 1.38 (95% CI 1.20-1.58, p<0.001).
Mentions warfarin · 2015
Interaction between warfarin and Chinese herbal medicines
Lin et al. · Stat Med
Dong quai listed among Chinese herbal medicines with documented warfarin potentiation via PD mechanism. Recommends caution when combining.
Mentions warfarin · 2014
Warfarin Interactions with Medicinal Herbs
Primary literature · Systematic review
Dong quai contains natural coumarin derivatives (ferulic acid, osthole) with documented antithrombotic and platelet-inhibitory effects. Animal steady-state studies show dong quai significantly increased prothrombin time WITHOUT affecting warfarin concentration - suggesting pharmacodynamic (not pharmacokinetic) interaction. Recommends informing patients of the potential hazard.
Mentions warfarin · 2008
Potential interaction of Ginkgo biloba leaf with antiplatelet or anticoagulant drugs: what is the evidence?
Bone · Mol Nutr Food Res
Reviews multiple controlled studies showing ginkgo does NOT significantly impact hemostasis or aspirin/warfarin safety. Notes EGb 761 (standardized extract) is not generally implicated in case reports. Quality of published case reports is low. Mechanism (ginkgolide B as PAF antagonist) is real but clinically modest.
Other interactions to know
K2 also reverses warfarin's effect
Salvia miltiorrhiza potentiates warfarin
Vitamin K directly antagonizes warfarin. Consistency of intake, not avoidance, is the right clinical approach.
Fish oil may increase bleeding risk with warfarin
High-dose vitamin E increases warfarin bleeding risk
Garlic supplements increase bleeding risk
Dong quai contains natural coumarins and has potentiated warfarin in a published case, raising bleeding risk.
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