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When to Stop a Supplement Before Surgery

This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — consult your healthcare provider before starting any supplement. Full disclaimer

Many common supplements — especially those affecting bleeding (fish oil, vitamin E, garlic, ginkgo, ginger) or sedation...

Many common supplements — especially those affecting bleeding (fish oil, vitamin E, garlic, ginkgo, ginger) or sedation (valerian, kava, St. John's wort) — can complicate surgery and anesthesia. Surgeons commonly advise stopping most supplements about 1–2 weeks before a scheduled operation, but the right timing depends on the product and your surgery, so always tell your surgical team everything you take.

Key Takeaways

  • Supplements affecting bleeding (fish oil, vitamin E, garlic, ginkgo, ginger) or sedation (valerian, kava, St. John's wort) can complicate surgery.
  • Surgeons commonly advise stopping most supplements about 1–2 weeks before a scheduled operation.
  • St. John's wort's enzyme effects can persist for up to two weeks, altering how drugs are handled.
  • NCCIH and MedlinePlus both urge telling your provider about every supplement before procedures.
  • Timing varies and some nutrients should be continued — decide with your surgical team, not on your own.

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Why Supplements Matter Before Surgery

Surgery and anesthesia put specific demands on the body — controlling bleeding, maintaining blood pressure, and metabolizing anesthetic drugs. Several popular supplements can interfere with those processes. That's why the U.S. government's NCCIH advises people to tell their providers about all dietary supplements they take, including before operations, since some can affect bleeding risk or the response to anesthesia [1]. MedlinePlus likewise notes that some herbs interact with prescription and over-the-counter medicines, and urges telling your provider what you take [2].

Categories That Most Often Matter

Bleeding risk (antiplatelet/anticoagulant effects):

  • Fish oil (high-dose omega-3), vitamin E, garlic, ginkgo biloba, ginger
  • These can add to surgical bleeding, especially alongside blood thinners (see [Supplements and Medications](/learn/supplements-and-medications)).

Sedation / anesthesia interaction:

  • Valerian, kava, and others with sedative effects may deepen or prolong anesthesia.
  • St. John's wort speeds up drug-metabolizing enzymes and can alter how anesthetic and other drugs are handled.

Other concerns:

  • Some products affect blood pressure or blood sugar.
  • Herbs like ashwagandha warrant disclosure too (see [Ashwagandha Safety](/learn/ashwagandha-safety-nccih)).

The Usual Timing

A widely used precaution is to stop most supplements about 1–2 weeks before scheduled surgery [3] — enough time for effects on platelets and drug metabolism to clear. St. John's wort's enzyme effects, for instance, can persist for up to two weeks. However, timing varies, and some prescribed supplements or nutrients should be continued — so this is a decision to make *with* your surgical team, not on your own.

What to Do Before a Procedure

1. Make a complete list of every supplement and dose, including 'natural' and occasional ones.

2. Share it with your surgeon and anesthesiologist at the pre-op visit — well before the date.

3. Follow their specific instructions on what to stop and when; don't guess.

4. Don't suddenly stop prescribed medications — ask which of those continue.

The goal isn't to fear supplements — it's to make sure your surgical team has the full picture so they can keep you safe.

Frequently Asked Questions

How long before surgery should I stop supplements?

A common precaution is to stop most supplements about 1–2 weeks before a scheduled operation, which allows time for effects on bleeding and drug metabolism to fade. But the right timing depends on the specific product and procedure, so confirm with your surgeon rather than relying on a general rule.

Which supplements matter most before surgery?

Those affecting bleeding — high-dose fish oil, vitamin E, garlic, ginkgo, and ginger — and those with sedative effects like valerian and kava. St. John's wort is also notable because it changes how the body processes many drugs. Tell your team about all of them, not just these.

Why does my surgical team need to know about supplements?

Because some supplements can increase bleeding, deepen or prolong anesthesia, or change how anesthetic and other drugs are metabolized. NCCIH specifically advises disclosing supplements before operations so the team can plan safely and avoid surprises.

Should I stop all my supplements and medications before surgery?

Not on your own. Some supplements should be paused and some prescribed medications must be continued, so this is a decision for your surgeon and anesthesiologist. Bring a complete list to your pre-op visit and follow their specific instructions on what to stop and when.

References

  1. National Center for Complementary and Integrative Health (NCCIH) (2024). Using Dietary Supplements Wisely. NIH National Center for Complementary and Integrative Health.
  2. MedlinePlus, U.S. National Library of Medicine (2024). Herbal Medicine. MedlinePlus (NIH National Library of Medicine).
  3. American Society of Anesthesiologists (2024). Herbal and Dietary Supplements and Anesthesia. American Society of Anesthesiologists.