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  • Writer's pictureJoan Rothchild Hardin

Blood Thinning Supplements & Foods to Avoid Before Surgery

Source: The JB Bardot Archives

Blood thinning medications are designed to prevent dangerous clot formation inside the body, not to actually make the blood thinner or break up existing clots.

Doctors tell you to avoid blood thinners for some time before surgery (two weeks to one day) to reduce your risk of prolonged bleeding during the operation but the list they give you usually includes only OTC and prescription blood thinners – and perhaps vitamin E.  Here’s a typical list:

  • Aspirin

  • Ibuprofen (Advil, Motrin)

  • Naproxen (Naprosyn, Aleve)

  • Clopidogrel (Plavix), warfarin (Coumadin), dabigatran (Pradaxa), rivaroxaban (Xarelto), apixaban (Eliquis)

          – ( MedlinePlus, 2019)




When I was getting ready for wrist surgery scheduled for August 30th a year ago, my orthopod required the results of several tests, including some blood work, by August 23rd in order to clear me for the surgery. It was early August and most internists I contacted were either going on vacation, didn’t do pre-op testing or wouldn’t take a new patient.

I finally found a young MD internist with a large, hip practice in my neighborhood who was willing to do all the required pre-op testing and could see me on August 14.

His office said it could take a week for them to receive the blood results. Not hearing anything from either the internist ‘s or surgeon’s office, I assumed all was well. Then, when I called the internist on August 24th, six days before the surgery, to get a copy of the blood results for my records, I was told told my clotting factors were quite elevated so he hadn’t sent a Medical Clearance letter to my surgeon. He also hadn’t let me know about this problem.

The internist asked if I was taking Warfarin, bruised easily, had bleeding gums. No, no & no. He was alarmed by my clotting factor results and wanted me to see a hematologist immediately to find out what was going on.

I suggested the results were probably from the nutritional supplements I was taking and told him I’d been off them since the 21st (10 days pre-op). Fortunately, he recognized he’d made a mistake and had me come in that same day to get my blood retested.  And mercifully, he was also willing to order the lab to process the new blood STAT so the results would come back later that day or Saturday morning. Saturday morning his nurse practitioner called to say my clotting factors were now normal and they’d faxed a Medical Clearance letter to my surgeon.

I’d given the internist a list of all my supplements and their doses when I’d seen him on the 14th. His reaction on the 24th was :’Yes, but we don’t know what those things are”.

On the positive side, I learned that those supplements are highly successful in promoting circulation and it’s unlikely I’ll ever get a dangerous blood clot. Also, they apparently clear the system in a day or so, unlike pharmaceuticals.

Source: Cure HHT


“Many people assume that just because a product is labelled as “natural”, it is harmless. The truth is that many powerful drugs (and poisons) are based on natural substances, so it’s clear that many natural substances can have a potent effect on the body. If this seems surprising, hemlock is “natural” and “plant-based” and can even be grown organically, but it didn’t do much for Romeo and Juliet’s relationship.” (Kita, 2019)

Turns out there are many other natural blood thinning/ anti-clotting substances that you’d do well to avoid before surgeries.

Below is a partial list of herbal supplements that belong on that list because they either:

  • are known to have blood thinning properties and may also interact with other blood thinners

  • are known to interact with blood thinners and therefore should be avoided

These are associated with increased bleeding:

  • Vitamin E

  • Ginko Biloba

  • Garlic

  • Ginseng

  • Ginger

  • Dong Quai

  • Ephedra

  • Feverfew

  • St. John’s Wort

  • Omega 3 fatty acids (fish oils)

  • Green tea

  • Saw palmetto

  • Glucosamine sulfate

– (Kita, 2019), (Blitz, 2012) & (Francis, 2019)

Supplements can have cardiovascular effects:

  • Ephedra (causes hypertension, palpitations, and tachycardia)

  • Garlic (can cause hypotension)

  • Ginseng

  • Kava

     -(Kita, 2019)

Supplements That Can Cause Drug Interaction:

  • Echinacea

  • Goldenseal

  • Licorice

  • St John’s Wort

  • Kava

  • Valerian

  • Selenium

  • Milk Thistle

  • Cannabidiol (CBD)

     – (Kita, 2019), (Cox, 2017), (Penn State Hershey Medical Center, 2017) & (CBD School, 2019)

Supplements That Can Have Anesthetic Effects:

  • Valerian

  • St John’s Wort

  • Kava

– (Kita, 2019)

Supplements Known to Cause Other Types of Adverse Events:

  • St John’s Wort (can cause photosensitivity, especially after laser or chemical peels)

  • Ginseng (can cause hypoglycemia)

– (Kita, 2019)

Source: Medical News Today


  • Turmeric

  • Ginger

  • Garlic

  • Oily fish (eg, albacore tuna, anchovies, herring, mackerel, salmon & lake trout)

  • Kiwi

  • Cranberries

  • Blueberries

  • Strawberries

  • Grapes

  • Cherries

  • Oranges

  • Tangerines

  • Prunes

  • Raisins

  • Walnuts

  • Cayenne pepper

  • Cassia cinnamon

  • Curry powder

  • Paprika

  • Dill

  • Oregano

  • Peppermint

  • Thyme

  • Licorice

  • Olive oil

  • Onions

  • Maitake mushrooms (hen of the woods)

     – (Leonard, 2018), (, 2017) & (RxList, 2019) My lists above aren’t comprehensive so please take some time to google the specific supplements you take to check if they also have blood-thinning properties. – and also include those supplements on the Pre-surgery Checklist you give your doc.

Source: Marmaris Turkey

See also


Blitz, N. (2012). What Vitamins Should You Take Before Surgery? While several vitamins, minerals and amino acids are used during healing, there are specific ones that are known to specifically to support the normal response to healing, and to support the normal immune system response to infection. See:

CBD School. (2019). CBD and Drug Interactions: An Easy Guide – CBD School. See:

Cox, L. (2017). Selenium — Supplement Facts and Effects – Live Science. See: (2017). Blood-Thinning Foods to Avoid. See:

Francis, G. (2019). Personal communication.

Jarrow Formulas. (2019). Milk Thistle Silymarin. See:

Kita, N. (2019). Herbal Supplements to Avoid Before Surgery. See:

Leonard, J. (2018).  Blood-thinning foods, drinks, and supplements. See:

MedlinePlus. (2019). The night before your surgery. See:

Penn State Hershey Medical Center. (2017). Milk Thistle. See

RxList. (2019). Maitake Mushroom. See:

Smarter Reviews. (2019). The Best Liver Health Supplements Of 2019: Learn what to look for and avoid when choosing a quality supplement for improved liver health. See: © Copyright 2019. Joan Rothchild Hardin. All Rights Reserved.

DISCLAIMER:  Nothing on this site or blog is intended to provide medical advice, diagnosis or treatment.


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