Most surgical centers ask you to stop all vitamins, supplements, and herbal products at least 7 days before surgery, though many specific supplements need a full 2 weeks. The American Society of Anesthesiologists recommends stopping all herbal medications 2 to 3 weeks before an elective procedure. The exact timeline depends on what you’re taking, because different products carry different risks.
The General Timeline
The simplest rule many hospitals use is to discontinue all vitamins, supplements, and herbals 7 days before surgery. That blanket guideline covers the majority of products most people take. But for herbal supplements specifically, the ASA’s recommendation is more conservative: 2 to 3 weeks before your procedure. The reason for this gap is that herbal products tend to have more unpredictable interactions with anesthesia and blood clotting than standard vitamins do.
Your surgeon’s office will likely give you a specific date to stop. If they don’t bring it up, ask. Surgical teams need to know everything you’re taking, including products you might not think of as “medication,” like fish oil, turmeric, or herbal teas.
Supplements That Need a Full Two Weeks
A long list of popular supplements carry enough risk that the standard recommendation is to stop them at least 14 days before surgery:
- Fish oil (omega-3s): At doses of 3 grams or more per day, omega-3 fatty acids interfere with platelet function. They compete with the compounds your body uses to form blood clots, reducing the production of clot-promoting molecules and increasing anti-clotting ones.
- St. John’s wort: This is one of the most concerning supplements for surgery. It speeds up the liver enzymes that break down many medications, which can weaken the effect of anesthetic drugs.
- Valerian root: Can amplify the sedative effects of anesthesia, making it harder for your anesthesiologist to manage how deeply you’re sedated.
- Kava: Similar to valerian, it can intensify sedation from anesthetic agents.
- Ginseng: Can cause drops in blood sugar and cardiovascular instability during surgery.
- Echinacea: Raises the risk of drug interactions by affecting liver enzyme activity.
- Saw palmetto: Increases the risk of postoperative bleeding.
- Arnica, dong quai, goldenseal, licorice, ephedra: All carry either bleeding risks or significant drug interactions that require a two-week washout.
A few supplements have shorter windows. Garlic and ginger supplements should be stopped at least 7 days before surgery. Ginkgo biloba has the shortest recommended window at 36 hours, though many surgeons will still ask you to stop it a week or two out to be safe.
Why These Products Cause Problems
The risks fall into three main categories: bleeding, anesthesia interference, and blood pressure or blood sugar instability. Bleeding is the most common concern. Supplements like fish oil, garlic, ginkgo, and ginseng all reduce your blood’s ability to clot normally, which matters when a surgeon is making incisions and your body needs to control blood loss on its own.
Anesthesia interactions are harder to predict and potentially more dangerous. St. John’s wort is a prime example. It ramps up liver enzymes responsible for processing a wide range of drugs, meaning anesthetics, painkillers, and other surgical medications can be broken down faster than expected. The result is that standard doses may not work as well. Valerian and kava work the opposite way, amplifying sedation so the anesthesiologist’s usual dosing could put you under more deeply than intended.
The 7-to-14 day timeline exists because that’s how long your body needs to fully clear these compounds and for their effects on platelets, liver enzymes, or the nervous system to wear off. Platelets in your blood live about 7 to 10 days, so supplements that impair platelet function need at least that long to cycle out of your system.
Vitamins You Can Likely Keep Taking
Not everything needs to stop. Standard-dose vitamins A, B12, and C taken at their recommended daily amounts do not typically need to be discontinued before surgery. A basic daily multivitamin that contains these at normal levels is generally fine as well, though your surgical team may still ask you to pause it just to simplify things.
Vitamin D and calcium prescribed for a documented deficiency are another common exception. Froedtert’s perioperative guidelines note that these may need to continue through surgery if you’re taking them to correct a deficiency rather than as a general wellness supplement. The key distinction is whether a doctor prescribed it for a specific medical reason or whether you’re taking it on your own.
If you take high-dose vitamin E, that’s a different story. High doses of vitamin E have antiplatelet effects similar to fish oil and should be stopped on the same timeline as other blood-thinning supplements.
What to Do If Surgery Is Urgent
These timelines apply to elective, planned procedures. If you need emergency surgery and you’ve been taking supplements, your surgical team will manage the situation. They have tools to monitor clotting in real time and can adjust their approach accordingly. If there’s any flexibility in timing, even delaying 12 to 24 hours can help reduce the influence of recently taken supplements. The important thing is to tell your surgical team exactly what you’ve been taking, including doses and when you last took them.
Resuming Supplements After Surgery
When you can restart depends on the type of surgery and how your recovery is going. For most procedures, your surgeon will give you the green light to resume vitamins and supplements once you’re eating normally and any bleeding risk from the surgical site has passed. That’s often 1 to 2 weeks after surgery, but it varies.
Bariatric surgery is a special case. Because these procedures change how your digestive system absorbs nutrients, vitamin and mineral supplements become essential immediately after surgery and for the rest of your life. Your surgical team will provide a specific supplement schedule that starts within days of the procedure.
For all other surgeries, bring your full supplement list to your post-op appointment and confirm which ones are safe to restart. Anything that affects clotting, like fish oil or vitamin E, should wait until your surgeon confirms your wound is healing well.