If you take vitamins, herbal products or sports supplements, your surgical team needs to know before your operation. Many websites go further and say “stop all supplements two weeks before surgery”. The real picture is more nuanced. This guide explains why supplements matter for surgery, what professional sources say about timing, and how to prepare a list for your pre-operative visit. It does not tell you which of your products to stop, because that depends on the product, the operation and your health.

Key takeaways

  • Anesthesiologists say some supplements can prolong anesthesia, increase bleeding, raise blood pressure or interact with other medicines, and that many patients never mention them.
  • The often-quoted two-week stop is described as a case-by-case recommendation, and a 2026 review argues for individual intervals from none to about three weeks.
  • Surgical and anesthesia teams decide which products to pause; the usual advice is to bring a full list, with labels, to the pre-operative visit.

Why do surgeons and anesthesiologists ask about supplements?

The American Society of Anesthesiologists (ASA) has a patient brochure, Herbal and Dietary Supplements and Anesthesia (2020). It says that, like some prescription and over-the-counter medicines, supplements can cause problems during surgery. It lists five ways they can increase risk:

  • They can prolong the effects of anesthesia.
  • They can increase the risk of bleeding.
  • They can raise blood pressure.
  • They can interfere with other medications.
  • They can cause heart problems.

The brochure adds that supplements are not closely inspected by the US Food and Drug Administration, so companies do not have to prove them safe or effective, and ingredient levels can vary between products. It also says studies show half of people who use herbal supplements do not tell their doctors before surgery.

For examples, the ASA lists ephedra, garlic, ginkgo, ginseng, kava, St. John’s wort, valerian and vitamin E, and describes the concern for each, such as increased bleeding or a stronger or longer anesthetic effect. This is a list of reasons to disclose a product, not a list of what to stop.

What does the research say?

A review in JAMA in 2001 by Ang-Lee and colleagues looked at the most common herbal medicines. It identified eight (echinacea, ephedra, garlic, ginkgo, ginseng, kava, St. John’s wort and valerian) that may pose a concern in the period around surgery. It describes direct effects such as bleeding from garlic, ginkgo and ginseng, cardiovascular instability from ephedra, and drug interactions: kava and valerian can increase the sedative effect of anesthetics, and St. John’s wort can speed up the metabolism of many drugs used in surgery. Its conclusion was that physicians should explicitly ask about and record herbal use, and understand the effects of both the herbs and stopping them.

A newer 2026 narrative review in Cureus covers plastic surgery patients specifically. The authors note that substances such as supplements, high-dose vitamins, herbal products, sports aids and weight-loss preparations are often left out of the pre-operative interview because patients do not think of them as medicines. They link several of them to bleeding, unstable blood pressure under anesthesia, drug interactions and impaired wound healing “to varying degrees”. They also propose a framework with graded suspension intervals “ranging from none to about three weeks”, rather than a single flat recommendation, and say that some substances are best avoided altogether. It is a narrative review from Brazilian surgeons, so it is expert opinion, not a trial.

How long before surgery do people stop supplements?

There is no single answer in the sources. The ASA brochure says only that in some cases your physician anesthesiologist may recommend you stop taking supplements at least two weeks before your procedure. The 2026 review aims to move practice beyond a generic “two weeks” rule and proposes a range from none to about three weeks depending on the product and the operation. I found no trial that tests a washout period for individual herbs.

So the often-repeated advice to “stop everything two weeks before” is a rule of thumb, not a standard, and it can be wrong in both directions: too long for some products, and not enough for others. Stopping some products suddenly can also have effects, which is another reason the decision belongs to the team that knows your health.

What should you bring to the pre-operative visit?

  • Every product you take, including vitamins, minerals, herbal teas, protein powders, pre-workout products, weight-loss pills and anything bought abroad or online. The ASA suggests bringing the bottles.
  • The exact name, the dose on the label and how often you take it. Names and ingredients can differ between countries, so a photo of the label helps.
  • The date you last took each one.
  • Your prescription and over-the-counter medicines, since the same team needs the complete picture.

If you are travelling for surgery, send the list to the clinic in writing before you book flights, and keep a copy. Ask who at the clinic will review it, and whether they will confirm the plan for each product in writing.

What should you ask?

  • Which of my products need to stop, and for how long before surgery?
  • When can I restart each one, and who tells me?
  • Do any of them matter for the type of anesthesia I will have? Our guide to general anesthesia for nose surgery explains the basics.
  • What should I do if I have already taken something I forgot to list?

For the rest of your preparation, see our checklist what to do before nose surgery. Food and supplements during recovery are a separate topic; guidance there is covered in nutrition after rhinoplasty, and what you take before surgery can differ from what your surgeon advises afterwards. Bleeding after surgery is covered in nose bleeding after rhinoplasty.

Sources

All pages were opened and checked on 10 October 2026.