Should I stop supplements before surgery? What to ask your surgeon

Do not guess and do not decide alone. Tell your surgeon and anesthesiologist about every supplement you take, bring the bottles to the pre-surgery visit, and let the team tell you what to stop and when. The American Society of Anesthesiologists says that in some cases the anesthesiologist may recommend stopping supplements at least two weeks before a procedure, but the right answer depends on the product, your health and the operation.

This guide covers why supplements matter for surgery, what the main sources say, the questions to ask, and how to handle a label that hides its amounts.

Why do supplements matter before surgery?

Surgery and anesthesia change how your body handles bleeding, blood pressure and drug processing. A supplement that does nothing noticeable on an ordinary day can still matter in an operating room. The American Society of Anesthesiologists (ASA) patient brochure lists five ways supplements can raise the risk of a procedure: they can prolong the effects of anesthesia, increase bleeding, raise blood pressure, interfere with other medications and cause heart problems. It adds that this can be true even if you have taken the supplement for years without trouble.

The same brochure explains why the surgical team cannot assume a product is predictable. Supplements are not closely inspected by the FDA the way prescription drugs are, the companies that make them do not have to prove they are safe or that they work, and the ingredient levels in a product can vary.

The National Center for Complementary and Integrative Health (NCCIH) says the same thing in shorter form: certain dietary supplements may increase the risk of bleeding or affect your response to anesthesia, so talk to your health care providers as far in advance of the operation as possible and tell them about every supplement you take.

Which supplements do surgical sources single out?

Three sources are worth knowing, and they do not agree on every herb. That disagreement is a reason to ask, not a reason to pick the version you like.

• The ASA brochure names ephedra (blood pressure and heart rate), garlic (bleeding), ginkgo (bleeding), ginseng (heart rate and bleeding), kava (stronger anesthesia effect), St. John's wort (may prolong anesthesia effects), valerian (may prolong some anesthesia effects) and vitamin E (bleeding and blood pressure).
• A 2001 JAMA review by Ang-Lee and colleagues examined eight commonly used herbs: echinacea, ephedra, garlic, ginkgo, ginseng, kava, St. John's wort and valerian. It reported bleeding from garlic, ginkgo and ginseng, cardiovascular instability from ephedra, low blood sugar from ginseng, and stronger sedation from kava and valerian. It also reported that St. John's wort speeds up the metabolism of many drugs used around surgery.
• A 2022 review by Hatfield and colleagues searched PubMed for bleeding risks. It found that garlic and hawthorn were strongly associated with surgical bleeding even without blood thinners, and that cordyceps, echinacea and aloe vera were loosely associated. It reported that fish oil, ginseng and saw palmetto were not associated with bleeding, and called the evidence on St. John's wort, ginger, ginkgo and cranberry conflicting.

Notice the ginseng split. The ASA brochure and the JAMA review flag ginseng for bleeding, while the 2022 review found no bleeding association. A plain reading is that the evidence is mixed and the surgical team has to weigh it for your case. The one point all three agree on is the same: report it, and plan the timing in advance. The 2022 authors recommend discontinuing nonessential supplement use two weeks before surgery, which matches the ASA's "at least two weeks" for some patients.

Do you have to stop everything two weeks before?

Not necessarily, and you should not make that call yourself. "Two weeks" is a figure that appears in the ASA brochure and in the 2022 review, but the review applies it to nonessential supplements, and the ASA words it as something the anesthesiologist "may recommend." Some supplements may need no change; some may need a different timeline. A supplement that was prescribed by a clinician for a documented deficiency is a different conversation from a general wellness capsule.

Do not stop prescription medicine on your own either. MedlinePlus advises people who take warfarin to tell the doctor or dentist about any surgery or procedure, and says the doctor may tell you to stop or change the dose before it. That decision belongs to your prescriber and your surgical team. A supplement review does not change it.

If you are not sure whether something counts, ask anyway. Vitamins, protein powders, greens drinks, teas and "nitric oxide" or "metabolism" powders all count. If it goes in your mouth on a regular basis, put it on the list.

What do real supplement labels look like to a surgical team?

A surgeon can only evaluate what they can read. Several offers we audited include ingredients that appear in the surgical sources above, and some do not publish amounts at all. We are describing the labels, not predicting what any capsule will do.

• iGenics lists ginkgo biloba as its main ingredient, along with bilberry and turmeric, and our review found no milligram amount for any of them. Our review already advises people on blood thinners to check with a doctor.
• Nitric Boost names eight ingredients, including ginkgo biloba powder and niacin, and our review found no amount for any of them on the sales page.
• Pineal Guardian X lists nine ingredients, including ginkgo biloba, with no supplement facts panel and no amounts. It also names no company on the page we reached.
• ProstaVive is a rare case where most amounts are printed. It lists 50 mg of Panax ginseng extract, which our review noted is below the range used in most ginseng studies. Even so, the surgical sources above do not offer a dose below which the question goes away, so it still goes on the list.
• Ikaria Lean Belly Juice puts Panax ginseng root and turmeric root inside a 1,000 mg metabolic blend, with no individual amounts for the nine ingredients in it.

The practical point: when a label hides amounts inside a blend, the person who most needs the number is your anesthesiologist, and the product cannot give it to them. If you cannot read the amount, say so. A photo of the label and the sales page ingredient list is a reasonable thing to bring.

Which questions should you ask your surgical team?

Bring the list below to your pre-surgery appointment. Write the answers down, because you will be given instructions about food, drinks and medicines in the same conversation.

1. Here is every supplement, vitamin, powder and tea I take. Which of them should I stop before the procedure?
2. How many days before surgery should I stop each one?
3. Does the type of anesthesia or the type of surgery change that advice?
4. I take a prescription medicine for blood pressure, blood thinning or another condition. Does a supplement change anything about how you plan my care?
5. When can I restart each supplement after surgery, or should I skip it for good?
6. If I cannot find an amount on the label, is it safer to stop that product entirely?
7. Who should I call if I realize I forgot to mention something?

Our medical disclaimer applies to everything here: we audit offers and summarize published sources, and we are not a substitute for your surgeon. If you want to see how a few offers that touch on circulation or blood vessels were scored, the men's health category is one place to start.

FAQ

Should I stop supplements before surgery?

Ask your surgeon and anesthesiologist before you stop or continue anything. Two published sources, the ASA brochure and a 2022 review, mention two weeks, but they frame it as a recommendation the team makes for you, and the review limits it to nonessential supplements.

Which supplements are most often named as a concern?

Garlic, ginkgo, ginseng, vitamin E, kava, St. John's wort, valerian and ephedra appear in the ASA brochure. The 2022 review adds hawthorn and calls the evidence on several others mixed, which is why you should list everything you take.

What if my supplement has a "proprietary blend" with no amounts?

Tell the team it is a blend and bring a photo of the label. They can then decide whether to ask you to stop it. A blend that hides its amounts makes it harder for anyone to judge, which is a reason to lean toward stopping with their approval.

What if my surgery is urgent and I forgot to mention a supplement?

Tell the nurse or anesthesiologist as soon as you remember, before the procedure if at all possible. The ASA notes that many people do not mention supplements to their doctors before surgery, so the team is used to being asked.