Supplements to Stop Before Surgery: What to Pause, What to Keep, and When

Written by Dr. Kevin Collon, MD — Orthopedic Sports Medicine & Shoulder Surgeon

Key Takeaways

• Most surgical teams ask you to pause herbal and "blood-thinning" supplements 1 to 2 weeks before surgery. Some hospitals ask for 2 to 3 weeks. Your surgeon's or anesthesiologist's instructions always come first.
• The main concerns are bleeding, blood pressure and heart rate changes, and interactions with anesthesia. Garlic, ginkgo, ginseng, vitamin E, turmeric/curcumin, kava, valerian, St. John's wort and ephedra come up most often.
• Not every supplement needs to stop. Protein, essential amino acids, vitamin D and vitamin C are part of standard pre-surgery nutrition, and many patients are told to keep eating and drinking enough protein right up to the fasting window.
• Fish oil is a gray area. A 1,516-patient randomized trial found no increase in bleeding with perioperative fish oil, but many hospitals still list it. Ask your team.
• Bring a list, or photos of the labels, to your pre-op appointment. That's the single most useful thing you can do.

Why supplements matter before surgery

Many patients don't think to mention their supplements because they "aren't medications." Your anesthesiologist needs to know anyway. Some herbs and high-dose vitamins affect how your blood clots, how your heart and blood pressure respond during anesthesia, or how your body processes other drugs.

The American Society of Anesthesiologists says your physician anesthesiologist may ask you to stop supplements at least two weeks before your procedure. Cedars-Sinai advises stopping all herbal supplements two to three weeks before surgery. A widely cited review in JAMA laid out the perioperative risks of the most common herbal medicines and is still the basis of many hospital handouts.

The exact timing varies by hospital, procedure and your own health, so use this guide to prepare questions, not to replace your surgical team's instructions.

Supplements commonly stopped before surgery

The risks in this table come from the ASA patient guide and hospital pre-op instructions such as Kaiser Permanente's, which name vitamin E, ginkgo, garlic, ginseng and ginger. For turmeric, the NHS Wales Medicines Information Centre advises stopping it at least two weeks before elective surgery.

What about fish oil?

Fish oil (omega-3 EPA and DHA) has long been on "stop before surgery" lists because omega-3s can slightly prolong bleeding time in the lab. The clinical evidence is more reassuring than those lists suggest.

In the OPERA trial, 1,516 cardiac surgery patients were randomized to high-dose fish oil (8–10 g over 2–5 days before surgery, then 2 g per day) or placebo. Major bleeding was not higher with fish oil (5.5% vs 6.6%), and patients in the fish oil group actually needed fewer blood transfusions. A 2025 review of perioperative omega-3 use reached a similar conclusion across many studies.

That said, your hospital may still ask you to stop. If you take fish oil, or a pre-surgery formula that contains omega-3s, show the label to your surgeon and follow their call.

Supplements that are usually fine, and often helpful

Stopping everything isn't always the safest choice. Patients who go into surgery poorly nourished do worse. In joint replacement, low blood albumin, a marker of poor nutrition, is linked to higher rates of complications, readmission and longer hospital stays.

These are commonly continued until the fasting window, unless your team says otherwise:

• Protein and essential amino acids (EAAs). In a randomized trial in knee replacement patients, 20 g of EAAs twice daily, starting 7 days before surgery, reduced muscle loss compared with placebo.
• Vitamin D. Low vitamin D is linked to higher complication rates after hip and knee replacement. Many surgeons test and correct it before surgery.
• Vitamin C. It's needed to build collagen. Standard doses are generally not a concern, though very high doses appear on some hospital lists, so mention them.
• Iron, if prescribed. About 1 in 5 joint replacement patients is anemic before surgery, and treating it reduces the need for transfusion.
• Creatine. It's safe in healthy kidneys, but it can raise blood creatinine, a kidney lab value, so tell your team you take it. People with kidney disease should avoid it, according to a review for orthopedic surgeons.

How OVIAL is designed around this

The OVIAL Surgical Nutrition Kit is split into two phases because of these timing issues:

• OVIAL PRE (the 14 days before surgery) contains essential amino acids, collagen peptides, vitamin D, vitamin C and omega-3s. It contains no curcumin or herbal ingredients.
• OVIAL POST (after surgery) adds curcumin and creatine, which you start once your surgeon clears you to resume supplements.

Bring the PRE label to your pre-op visit, especially because it contains omega-3s, and follow your team's advice on whether to continue it through the day before surgery.

A simple pre-op supplement checklist

1. 3–4 weeks before: List every supplement, vitamin, powder, tea and "natural" product you take, with doses. Take photos of the labels.
2. At your pre-op visit: Hand the list to your surgeon or anesthesiologist. Ask specifically: "Which should I stop, and on what date?"
3. 2 weeks before: Stop what you were told to stop. Start any pre-surgery nutrition your surgeon recommends.
4. Day before: Follow your fasting instructions exactly. They override everything else.
5. After surgery: Ask when you can restart each supplement. Don't restart herbal or blood-thinning products while you're on prescribed blood thinners unless your team approves.

Frequently asked questions

Can I take vitamins before surgery?

Usually, yes. A standard multivitamin, vitamin D and vitamin C are typically fine. High-dose vitamin E is the main vitamin often stopped. See our guide to vitamins before surgery for more detail.

How many days before surgery should I stop turmeric?

Most guidance says about two weeks. Ask your surgeon when it's safe to restart, especially if you're on blood thinners after joint replacement.

Should I stop protein powder before surgery?

Generally no, as long as it doesn't contain herbal blends. Staying well-nourished before surgery is linked to fewer complications. Stop all food and drink when your fasting instructions say to.

What happens if I forgot to stop a supplement?

Tell your surgical team as soon as possible, ideally before the day of surgery. Don't hide it. They can decide whether anything needs to change.

This article is for general education and isn't a substitute for advice from your surgeon or anesthesiologist. Always follow your surgical team's instructions about supplements and fasting. OVIAL products are not intended to diagnose, treat, cure or prevent any disease.

References

1. American Society of Anesthesiologists. Herbal and dietary supplements and anesthesia.
2. Ang-Lee MK, Moss J, Yuan CS. Herbal medicines and perioperative care. JAMA. 2001.
3. Cedars-Sinai. What to know about herbs and surgery.
4. Akintoye E, et al. Fish oil and perioperative bleeding. Circ Cardiovasc Qual Outcomes. 2018.
5. NHS Wales Medicines Information Centre. Turmeric: potential adverse effects.
6. Dreyer HC, et al. Essential amino acid supplementation mitigates muscle atrophy after total knee arthroplasty: a randomized, double-blind, placebo-controlled trial. JBJS Open Access. 2018.
7. Emara AK, et al. Hypovitaminosis D in lower extremity joint arthroplasty: a systematic review and meta-analysis. J Orthop. 2020.
8. Hypoalbuminemia remains an independent predictor of complications following total joint arthroplasty.
9. Impact of preoperative anemia on patients undergoing total joint arthroplasty.
10. Creatine: clinical implications for orthopedic surgeons.