Quercetin vs Viruses (Powerful anti-viral properties of this unique nutrient)

By: Cat Ebeling, RN, MSN-PHN, co-author of the best-sellers:  The Fat Burning KitchenThe Top 101 Foods that Fight Aging & The Diabetes Fix

With the rapid spread of Covid-19 around the world, along with the dramatic and scary news stories, it seems everyone is scrambling to grab supplements to boost their immune systems. While nothing takes the place of a healthy diet that lowers inflammation in your body, a good night’s sleep, stress reduction, exercise, and vitamin D production in your skin from sun exposure—some supplements can definitely be helpful as well.

Once the SARS-CoV-2 or Coronavirus gets inside the human respiratory tract, it infects and multiplies in the cells lining the airways and lungs. This kicks the body’s immune system into action. In most people, the immune system does its work, then recedes and the patient recovers.

Normally, an immune response which causes inflammation is a normal and good thing in the fight against a pathogen or an injury. However, with this coronavirus, the Acute Respiratory Distress Syndrome that occurs in some people, happens as a result of a dysfunctional immune response to the presence of the virus. The uncontrolled immune response triggers an overproduction of immune cells and their signaling molecules which leads to a ‘cytokine storm’. This cytokine storm is generally what causes the severe and potentially fatal symptoms of severe pneumonia and breathing difficulties with a Covid19 infection.

So it’s more about having a healthy immune system overall and reducing inflammation in the body, because if the body is already overridden with inflammation, leaky gut, Diabetes, obesity, and other health problems, it’s possible this can contribute to the cytokine storm that’s being seen in some patients.

There are several supplements that actually help to strengthen the immune system and reduce inflammation, without overstimulating the immune system. One of the top nutrients for this is Quercetin.


What is Quercetin?  It is a potent anti-inflammatory and antiviral substance found in certain foods, including red onions and apples. Many people take Quercetin in the fall and spring to help their allergies to tree and weed pollen.  Quercetin has been shown in many studies to have fairly broad anti-viral properties against most viruses.

Quercetin is considered a bioflavonoid. Quercetin is found in the highest concentrations in red onions, berries, red wine, green tea, buckwheat, and apples.

Quercetin is now also undergoing trials in China for its effectiveness against Covid19 (but I am in no way saying Quercetin cures or blocks your ability to get it). In a recent analysis published by the University of Tennessee and Oak Ridge National Labs, they used high-powered computer modeling to look at which compounds or supplements might best prevent the coronavirus from binding to our cells.

This is key, because this is how this virus gets into to our bodies and starts reproducing. It enters our bodies through nasal passages, mouth, eyes, or respiratory passages. Once it binds to a cell, it finds its way into the cell, starts reproducing like crazy, and takes over the respiratory system, especially the lungs.

The coronavirus uses the ACE2 or Angiotensin Converting Enzyme receptor in our bodies to enter the cells. This is important too, because ACE2 receptors have to do with regulating our blood pressure—I’ll talk more about that below.

The analysis from Tennessee looked at several different compounds and nutrients to see which ones worked best at interfering with the virus’s ability to attach to a cell and get inside to do its damage. One of the top 5 virus-fighting natural compounds is Quercetin.

Quercetin is a natural supplement that has other big benefits including lessening reactions to allergies, as well as fighting aging and free radicals. Well worth it to start taking since it has multiple benefits for our health. According to most research, the usual dose is 500mg to 1,000 mg a day. Quercetin is often compounded with a digestive enzyme like bromelain, plus Vitamin C, to improve absorption. All good things.

Quercetin is also inexpensive, especially compared to some of the pharmaceutical grade antiviral drugs that are being used now. This broad-spectrum antiviral supplement has already proven successful for treating the Ebola and Zika viruses, according to Dr. Michel Chrétien, a researcher at the Clinical Research Institute of Montreal.

Does it work for sure? It’s too early for standard clinical trials to show positive proof, but the circumstantial evidence is strong in favor of its anti-inflammatory and antiviral capabilities. The best thing about quercetin is, even without clinical trials, we know that quercetin will not harm you, or cause your immune system to overreact. Including quercetin in your immune-boosting weapons seems like a wise idea, along with these other practices as well:

Get good sleep


Poor sleep increases the risk of infectious illness. One study found that getting less than 5 hours of sleep over the course of a week, can increase the chances of catching a cold by 350%. Also, important to note is that lack of sleep can increase inflammatory levels in the body, creating higher risk for a cytokine storm. If you are having trouble sleeping, a small dose of melatonin at night may help you sleep better and keep your immune system strong.

Manage your stress

It’s no secret that stress definitely disrupts our immune function and increases our levels of inflammation, making us far more susceptible to getting seriously ill. Stop reading the news, follow precautions and find something relaxing to do—meditation, breathing exercises and exercising outdoors all go a long way to manage stress, reduce anxiety and strengthen your immune system.

Take Zinc


Zinc has been proven to reduce the activity of coronavirus and may prevent its entry into our cells while reducing its power. Zinc has proven powerful in fighting off regular influenza and the common cold as well. The suggested dosage for zinc is about 15mg – 30mg daily.

Vitamin C


Vitamin C has shown great promise in inhibiting inflammatory reactions and is thought to be very effective against viruses as well.  Several clinical trials have found that vitamin C shortens the frequency, duration and severity of the virus that causes the common cold (a type of corona virus) and the incidence of pneumonia. Vitamin C can be taken in reasonably high doses as any excess is washed out of the body.

Eat Other Immune-Boosting Nutrients:

Other foods to consider including in your diet are garlic, fresh ginger, berries, green tea, and even grass fed butter and organ meat–full of vitamin A and other immune-boosting natural compounds.

Stay well, be healthy, and remember, a healthy body is the best defense against any disease.




About The Watchdog

Mike Geary has been a Certified Nutrition Specialist and Certified Personal Trainer for over 15 years now. He has been studying nutrition and exercise for almost 25 years, ever since being a young teenager. Mike is originally from Pennsylvania, but has fallen in love with mountain life and now resides in the picturesque mountains of Utah. Mike is an avid adventurist and when he’s not spending his time skiing, mountain biking, hiking, or paddleboarding on the lake, he has enjoyed skydiving, whitewater rafting, piloting an Italian fighter plane (seriously), scuba diving, heli-skiing, and traveling all around the world, enjoying learning about different cultures. At the age of 40, Mike now feels healthier, stronger, and more energetic than when he was 20... All because of a healthy lifestyle and great nutrition!

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  1. A brilliant letter on immunity and Covid 19 – thank you

  2. You didn’t say where or how we could buy a quercetin.

    • hello Margaret. Thank you for commenting and reading! It’s available at most health food stores and websites. It’s not a new supplement and people have been using it for a long time, so it’s readily available

      • Have you looked into the benefits of Acemannan? I’ve been taking for the last 3 years with only one minor cold.

        • Thanks so much. Which best plant food sources is quercetin in?

          I am trying to make use of nutrients vis food more so than supplements.


        • Apparently Camu Camu has a lot. I use the powder mixed into shakes several times a day.

    • Ruth Evelyn Smith

      Where can we buy Quercetin?

      • Gerald Marquardt

        I buy my supplements from Swanson Health and they are priced good

      • Gerald N. Yorioka, M.D.

        I am replying over a year later, but by now you should have abundant queercetan. But what should be said is that quercetan is the most abundant flavinoid in foods. At the top of the list is capers, which I happen to like, along with blueberries, green tea, and red wine, and among, I can manage at least one of them every day. But there may be a more important angle to this. Quercetan is an ionophore, which like hydroxycholorquin and ivermectin transports zinc into a cell. Zinc has been treated as a nice addition, but might be the main player, as it is structurally essential in what is called the zinc finger protein that loops a single strand of DNA or RNA in the natural repair process for damaged RNA or DNA. If that strikes a familiar chord, the Nobel Prize in 2020 to Doudna and Charpantier was for the discovery of a loop-snip-replace process for a single strand of RNA or DNA. As far as I know zinc or another double charged ion has not been described with this CRISPR-cas9 process. The mysterious notion that zinc is good to take for the common cold might have a simple explanation. If you take quercetan without taking zinc, it may still work, since there is always present some level of serum zinc, and the ionophore will deliver it into the cell or nucleus. If you think to take zinc, pop in two capers as a chaser.

    • I also would lie to buy Quercetin but don’t know where to find it. I asked my druggist but she said they don’t carry it! I also have asthma and severe sinus problems. I am very frightened of getting the virus as I also have high blood pressure and am over 80!

      • Quercetin is widely available online. Google amazon

      • Please try to find a Health Food Store in your neighbourhood. They ALL carry them at a reasonable price. Forget about drug stores or pharmacies because they carry drugs and QUERCETIN is not a drug. While there buy some zinc and vitamin C as well to take daily. Also eat more red onions, berries, apples, and drink green tea and/or wine every day. It will be good to eat a banana daily as well cos it helps lower blood pressure. Good heath to you Francine!

      • Google Highland Laboratories in Mt. Angel, Oregon.

        They sell a combo of Quercetin/Zing which has Vitamin C, D3, Zinc, Quercetin, Bromelain, and Nettle Root.

        You can’t ask for any better combo in 1 capsule.

        • Jennifer Fitzgerald

          Thanks for the wonderful recommendation!!! I’m going to check them out right now! I love supporting anything made here in the states. Thanks again!

    • MaryAnn E Boudreau

      The article mentions it is in apples, berries, red onions, red wine and another food.

    • Go online…Puritan Pride is a good one .

  3. Thank you for this vital and timely information. What studies are presently being done on the benefits of supplemental Vit D as it regards Acute Viral Respiratory Infections?

  4. Good article I have a aito immune disease it’s called Bronchitis it is weak bronco in my lungs if I get this I’m dead what can I do more I’m taking vit c .d bromilime apple sauce is t quercetin in mucinex. I est healthy all organic even my animals do what else I can do

    • Great info. Carolyn get some olive leaf extract , it should clear your lungs .Also oil of oregano . These two with the quercetin will build your immune system olive leaf by itself is over 100,000 on the orac scale . I’ve used the olive leaf and oil of oregano for bacterial infections and viruses. Do your research and good luck.

      • Jennifer Fitzgerald

        Thanks for sharing your knowledge on the use of these two supplements! I’ve been looking for anything to help get my body in fighting shape! Thanks again!

    • Tumeric is also a very good immune system booster and antiinflammatory. Fisetin can also be effective at getting rid of old less effective immune cells and replacing them with younger more effective immune cells.eating lots of cruciferous vegetables(broccoli cauliflower brussels sprouts can have a positive boost to immune function. Staying away from sugar and high carbs such as bread and pasta is recommended because eating sugar and carbs will suppress the immune system for 6-8 hours. Exercise can also help boost immunity.A15-30 minute walk 3-5 times pet week can be effective.


    • Chris the article was specifically about Quercitin, and Green Tea was actually mentioned in the article as a good source of this nutrient.

  6. The best broad spectrum antibacterial / antiviral I know of is ionic / colloidal silver. The powers that be know it too but they go far out of their way to suppress that information. If they told the sheeple that using silver with a nebulizer would destroy the virus quickly they wouldn’t have this crises to utilize to assault Capitalism the world over.

    • i agree with the colloidal silver. i use structured silver, another type, made in canada, and either bottled liquid or gel. it is excellent, either silver works well.

    • I had a virus in February and took and gargled extra colloidal silver Emergen-C and Zinc and used a nebulizer after having a cytokine storm episode and was over this undiagnosed flu in 10 days. I never had a storm like this before and it scared me but I got over it quickly and totally in 10 days with very few symptoms but for coughing up phlegm after the storm for about three days. During coughing I used my diffuser with colloidal silver in it realizing by breathing it into my lungs it was killing the virus.

      • Jennifer Fitzgerald

        Wow, that’s great news!!! I’m very happy for you that you were able to help your body get rid of it! That’s amazing! Humans really are stronger than we give ourselves credit for! Thanks everyone for the colloidal silver tip, I’ll definitely be putting that on my list of supplements to buy!

  7. What’s your opinion and/or do you have any information on oregano oil and oive leaf extract regarding immune system support? I have been taking the Kyolic, Immune Formula 103 for a couple of years and really haven’t gotten sick with anything in that time, flu’s or colds, and I only take half the daily recommended dose. It has Vit. C, aged Garlic, a mushroom complex with Shiitake, Maitake, Poria Cocos, Reishi and Agaricus, as well as Astragulus extract, Oregano extract and Olive Leaf extract.

    • where can i get kyolic, immune formula 103 in Southern Africa? I really appreciate theinformation and have been taking Reishicollagen and seem to be working wonders.

  8. Thank you for the valuable article, could you please provide me with a research paper recommend
    the in vivo use of Quercetin as antiviral?

  9. This is an awesome read, very informitive., can I give this to my cat??? I want to get some ASAP .. I’ve always taken vit c, zinc, vit D.. Tumeric, probiotic eleven, magnesium, B12, nutri-calm, & the circulatory system packets ( coenzyme Q10,fish oil, ginkgo& hawthorn, ),, could I add this on top of all of that ?? I do not believe in pharmaceuticals , although, for surgeries, & only in extreme emergencies .. I would, take them.. Do not like to…, too many side effects .. I’ve taken pharmaceuticals only 2 times the past 6 years.. I do not get a flu shot .. & will not.. My husband doesn’t take anything pharm either.. Thank u..

  10. I am a diabetic how will this affect me I am 72 years old but in Fairly good health

  11. Michelle Lewis Davis

    Would you recommend this for an over-weight teenager with severe sleep apnea?
    I’m afraid that she may vape and have noticed increased loud breathing during day with excessive loud coughing.
    She is very social and having a difficult time right now.

    • Try blending 2 cloves of garlic, equal amount of fresh ginger, a red apple, a tablespoon of lemon juice, a cup of water, plus a dash of honey daily. You could add a bit on onion and spinach if you are adventurous. Great natural antibiotic, helps burn body fat too unless there are underlying health issues like hormonal imbalances.

      Boil 2 tablespoons of dried parsley and drink it as tea to stop the smell of garlic, in fact, all smells in the body.

  12. Jewell Elizabeth Pope

    Thanks you very much this was and very helpful

  13. What is best supplements for oxidative stress? What is your suggestion about the advertisement of NRF2?

  14. Awesome article in these trying times……..brabo to the author

  15. charlotte oliver

    I like it.

  16. Sharon Blackwood

    Hi Dr Mike, don’t knw if u can help but I’ve been talking Metformin HCL 500 MG. & I’ve gained some 70 to 90 pounds. I’m now weighing 271, & I’ve been trying to loose weight but to no avail. I just read ur article abt Berberine, could u suggest a good brand for me to try. Pls Thnk u, Hope to hear fr u as soon as possible.

  17. IN SEVERE CASES OF COVID-19, a doctor found that there is a thrombo-phlebit (a clot that change location and go to the lungs arteries and block breathing process.

    What he does, is prescribe an ANTI-COAGULANT (to melt clot), and an ANTI-INFLAMMATORY to reduce inflammation.
    He says his patients are up and about within 3 days.

    • i wonder if you can just take a 325 or baby aspirin instead its still a blood thinner! Especially if your doctor wont prescribe it

  18. Pills, pills & more pills. Organic grown greens, vegetables, juices, nuts and seeds (plant based diet) is essential for optimal health.

    • A plant based diet is NOT the best type of diet, and could in fact make you a lot less healthy.

      • Thank you for this informative article. As to your comment above, my husband and I have been on the Blood Type diet (eating according to our blood type) for over 20 years. We both lost weight and our immune systems were strengthened. I’ve only been on antibiotics once during that time. We are both “A” blood type and therefore do not need much meat but instead eat more fruits and vegetables.
        I am sure you need more meat as perhaps you are an O blood type, but we’ve found everyone is individual. I am 67 years old, weigh 105 pounds, and am very healthy. It’s something worth looking into. http://www.dadamo.com

  19. Thank you for such a telling article. I didnt know alot of this information. I am a diabetic and cant control my sugar very well and I am on 2 inject insulins and I have heart disease and high blood pressure and chemical damaged lungs and I take about 12 pills a day for all this and I am scared to death I will get Covid. I needed to know all your info and I read everyone else information. I learned alot. Thank you. Glenda

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