Questions to Ask Before Surgery About Your Medications and Supplements

Surgery is one of the moments when an incomplete medication picture can cause real harm: a supplement that thins the blood, a medicine that clashes with anesthesia, or a dose taken on the wrong morning. Knowing the right questions to ask before surgery about medications and supplements — and asking them early enough to act on the answers — is one of the simplest ways to make your operation safer. This guide gives you the question list, plus how to prepare so the answers are accurate.

Key takeaways

• Tell your surgical team about every prescription, OTC medicine, vitamin, and supplement — herbal products can affect bleeding and anesthesia.
• Many supplements are stopped one to two weeks before surgery, but only on your team's product-by-product instructions.
• Blood thinners, aspirin, NSAIDs, and diabetes medicines need precise stop-and-restart plans from the prescriber.
• Get a written morning-of-surgery list saying exactly what to take with a sip of water.
• Ask when each stopped product should be restarted after the operation — restarting is forgotten more often than stopping.

The questions to ask before surgery about medications and supplements

Bring these to your pre-operative appointment and write down the answers next to each product on your list:

• Which of my medications should I stop before surgery, and exactly when should I take the last dose?
• Which supplements, vitamins, and herbal products should I stop, and how far in advance?
• What may I take on the morning of surgery, and with how much water?
• I take a blood thinner (or aspirin, or NSAIDs like ibuprofen) — who manages stopping and restarting it?
• I take diabetes medicine or insulin — how should doses change while I am fasting?
• When do I restart each stopped medicine and supplement after the operation?
• Will any new medicines after surgery, such as pain medicine, interact with what I already take?

Why supplements get special attention before surgery

Patients often skip supplements when listing their medicines because "they're natural" — but the American Society of Anesthesiologists specifically warns that common products can complicate surgery. Garlic, ginkgo, fish oil, and vitamin E can increase bleeding; ginseng can affect blood sugar and blood pressure; St. John's wort can change how anesthetic and pain medicines are processed; valerian and kava can deepen sedation. UT Southwestern's surgical guidance echoes the same theme: pause most supplements before an operation, on your team's schedule.

None of this means supplements are bad — it means the surgical team needs to know about every one of them. Disclose everything, including gummies, powders, teas taken for health reasons, and products you only use occasionally.

Blood thinners, NSAIDs, and diabetes medicines: the big three

Three groups of medicines account for many pre-surgery instructions. Prescription blood thinners are usually stopped on a precise schedule set by the prescriber, and sometimes bridged with another medicine. Aspirin and NSAIDs such as ibuprofen and naproxen can increase bleeding and are often held for several days — but only on your team's instruction, especially if you take aspirin for your heart. Diabetes medicines and insulin usually change dose on the fasting day. For all three, the key question is not just "do I stop?" but "who is responsible for telling me exactly when to stop and when to restart?"

Prepare a complete list before the pre-op appointment

The American College of Surgeons advises telling your surgical team about every medication and supplement you take. That works only if your list is complete. Gather every bottle, box, inhaler, patch, and supplement in the house and record the name, strength, dose, and how often you take it — including as-needed products. Put allergies and past reactions to anesthesia or pain medicine at the top; the anesthesiologist will ask.

How MedSafeScan helps before surgery

MedSafeScan makes the preparation step faster: scan your medication and supplement labels instead of typing them, keep prescriptions, OTC medicines, and supplements in one profile, and walk into the pre-operative appointment with a complete, current list on your phone. You can also note which products your team told you to stop and when, so nothing gets missed in the days before the operation. The stop-and-restart decisions themselves always belong to your surgical team.

MedSafeScan provides informational guidance only and is not a substitute for professional medical advice. Always consult your healthcare provider before making any changes to your medications.