Drug Interaction Report

Heparin and Ginkgo: Interaction Details

A pharmacist-reviewed analysis of the Heparin and Ginkgo interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Heparin

No brand names on record
+

Ginkgo

No brand names on record
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Major
Potentially serious — often needs a change or close monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Of 221 documented Heparin interactions, 169 are rated major — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
delayed
Evidence
probable
Severity
Major

What happens

Increased risk of bleeding

Interaction Deep Dive

Concomitant use of ginkgo and anticoagulants may increase the risk of bleeding complications. A 78-year-old female developed left parietal hemorrhage after two months of therapy with the combination of warfarin and ginkgo4. In contrast, ginkgo biloba had no effect on INR in patients stable on warfarin in a a randomized, double-blind, placebo-controlled, crossover trial 3. More frequent INR monitoring should be performed when starting or stopping ginkgo biloba 1.

Why it happens (mechanism)

Ginkgolide B may inhibit platelet activating factor (PAF) induced platelet aggregation

Literature reports

4 reports — tap to read

a) Intracerebral hemorrhage was reported in a 78-year-old woman following 2 months of concomitant ingestion of ginkgo (unspecified dose and type) and warfarin (unspecified dose). The patient had been stabilized on warfarin for 5 years following coronary artery bypass. The patient presented with a 2-day history of inability to feed herself. Brain CT scan revealed left parietal hemorrhage. PT was 16.9 seconds and PTT was 35.5 seconds (lab reference values not provided); no bleeding time was provided 5.

b) Ginkgo biloba did not affect the international normalized ratio (INR) in a randomized, double-blind, placebo-controlled, crossover trial of 24 patients stable on warfarin. Patients received ginkgo biloba 100 mg daily in addition to their regular warfarin therapy for four weeks, then crossed over to placebo after a two-week washout. The geometric mean warfarin dose remained the same and INR was unaffected during treatment 3.

c) Cases of subarachnoid hemorrhage, subdural hematoma, intracerebral hemorrhage, and postoperative bleeding have been reported in patients taking ginkgo alone 6728910.

d) Ginkgolide B has been shown to inhibit PAF-induced platelet aggregation 1112. Though a clinical trial demonstrated no effect of ginkgo on warfarin therapy 3.

Common questions

Can I take Heparin and Ginkgo together?

Increased risk of bleeding Always confirm with your pharmacist or prescriber before making any change.

How serious is the Heparin and Ginkgo interaction?

It is rated major. Potentially serious — often needs a change or close monitoring.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

How strong is the evidence for this interaction?

The evidence is graded "probable". Good supporting evidence, though not definitively proven.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Heparin or Ginkgo need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there a safer alternative to one of these medications for me?

References (12)

  1. Product Information: WARFARIN SODIUM oral tablets, warfarin sodium oral tablets. Teva Pharmaceuticals (per Dailymed), Parsippany, NJ, 2023. DailyMed
  2. Norred CL & Finlayson CA: Hemorrhage after the preoperative use of complementary and alternative medicines. AANA J 2000; 68:217-220.
  3. Engelsen J, Nielsen JD, & Hansen KF: Effect of coenzyme Q10 and gingko biloba on warfarin dosage in patients on long-term warfarin treatment. A randomized, double-blind, placebo-controlled cross-over trial (Abstract-Article in Danish). Ugeskr Laeger 2003; 165(18):1868-1871.
  4. Matthews M: Association of gingko biloba with intracerebral hemorrhage. Neurology 1998; 50:1933-4.
  5. Matthews M: Association of gingko biloba with intracerebral hemorrhage (letter). Neurology 1998; 50:1933-4.
  6. Benjamin J, Muir T, Briggs K, et al: A case of cerebral haemorrhage - can Ginkgo biloba be implicated?. Postgrad Med J 2001; 77(904):112-113.
  7. Fessenden JM, Wittenborn W, & Clarke L: Ginkgo biloba: A case report of herbal medicine and bleeding postoperatively from a laparoscopic cholescystectomy. Am Surg 2001; 67(1):33-35.
  8. Vale S: Subarachnoid hemorrhage associated with Ginkgo biloba. Lancet 1998; 352:36.
  9. Lewis SL & Rowin J: Ginkgo biloba. Neurology 1997; 48:1137.
  10. Rowin J & Lewis SL: Spontaneous bilateral subdural hematomas associated with chronic Ginkgo biloba ingestion. Neurology 1996; 46:1775-76. PubMed
  11. Wilkens JH, Wilkens H, Uffmann J, et al: Effects of a PAF-antagonist (BN 52063) on bronchoconstriction and platelet activation during exercise induced asthma. Br J Clin Pharmac 1990; 29:85-91. DOI
  12. Chung KF, McCusker M, Page CP, et al: Effect of a ginkgolide mixture (BN 52063) in antagonizing skin and platelet responses to platelet activating factor in man. Lancet 1987; 1:248-251.
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Heparin

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Ginkgo

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All Ginkgo interactions (70)
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Beyond drug–drug

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Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.