OnGuard Immune Defense

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Put Your Immune System OnGuard®!

Today we are under attack! A strong immune system is crucial. But, how good is your immune system? Many things can weaken your immunity:

  • If you don't eat right?
  • Lack sufficient sleep?
  • Don't have adequate levels of Vitamin A, D, or Zinc?
  • Suffer with certain chronic medical issues?
  • Are over 65 years of age?

No matter how healthy you are, with advancing age your immune system declines. When you get rundown, older, or weakened by stress, latent viruses within you can resurface.


Shield Your Health with OnGuard®

With all the challenges that plague us today, you need to support your immune system now more than ever. The OnGuard® formula goes beyond vitamins with Colostrum, rich in antibodies, Lo Han fruit extract used for centuries to preserve health, and MaitakeGold 404™ Mushrooms – proven "immune active" by University Scientists.

Take OnGuard every day to stay well, especially when you are on-the-go exposed to the public. You'll feel better and stay healthier!

 You Are Under Attack by Germs Daily.

What are You Doing to Protect your Health?

Germs are around us always, in the air we breathe, the surfaces we touch, and from the people we come in contact with each day.  Exposure to others in closed spaces increases risk: offices, stores, airplanes, trains, theaters, church, etc.

If someone coughs or sneezes, germ droplets can float in the air and assault the next victim. When you least expect it, you could be exposed to deadly bacteria and viruses. You need to keep your immune system ONGUARD®!


dr-schally.pngNobel Prize Laureate says OnGuard Works!
Dr. Andrew Schally is a world-renowned Scientist acclaimed for his ground-breaking health discoveries. He has published over 3,000 scientific papers, is 94 years old and works all day, starting his research at 7am.
"OnGuard is an excellent formula. I take it each day and make sure my wife does also. We feel the difference. We have taken OnGuard daily during the Pandemic and will continue to do so after for the rest of our lives!"


Put the Odds in Your Favor

Your good health relies on your body's immune surveillance system. It must identify and remove dangerous invaders 24/7 to keep you in the best of health. MDR OnGuard® contains powerful compounds from nature that have the ability to provide extraordinary immune support. The botanicals increase cell health and improve your defenses.


  • MycoFusion: Proven, patented mushroom extract enhances immune cell activity and increases cell defenses.
  • Colostrum: Transfers protective antibodies and immune factors derived from mother cow's first milk for her calves.
  • Lo Han Kuo: Chinese melon extract "Lo Han Kuo" prized for centuries to promote good health and longevity.
  • Lotus Seeds: Longest living seeds (1,288 years) revitalize your health. Supplies protective nutrients and antioxidants.



MycoFusion Powers Up Your Immunity

OnGuard's main ingredient MycoFusion™ combines Shitake Mushroom with a special extract derived from Maitake mushrooms. Japanese researcher Dr. Hiroaki Nanba, PhD. discovered that certain fractions isolated from Maitake mushrooms provided extraordinary immune-enhancing benefits. Naturopathic Doctors, Nutritionists and medical centers like Memorial-Sloan Kettering Center in New York have recognized MaitakeGold 404™ for its ability activate immune defenses.

The University of Louisville confirmed that MycoFusion™ is rich in Beta-Glucans that are "immune active". That means they can help activate your immune cells to be ready to defend you. Dr. Nanba's discovery of MaitakeGold 404™ was such a great advance that it was granted U.S. Patent #5,854,404, so there is nothing like it! Maitake Mushrooms can activate T-cells vital to the body's immune arsenal. It's one of the reasons why so many people enjoy great health from taking MDR OnGuard® Immune Defense.



Fortified with Colostrum Rich in Antibodies

Colostrum is the first milk produced by Mother cows to transfer their protective antibodies to their vulnerable newborn calves. This milk occurs only the first few days after a cow gives birth and is extremely rich in powerful immune factors.

Colostrum has been cited in hundreds of scientific medical journals for its effectiveness in improving health. From gut health to respiratory health, to overall wellness and performance, Colostrum has proven to be highly valuable.

Pure. Safe.

Made in the USA

The Colostrum used in MDR OnGuard® is certified as Grade A pasteurized and collected solely from US dairies that insure it is free of: Artificial Hormones, Antibiotics, Pesticides, GMO, and BSE.





MDR, a Name You Can Trust

MDR ships OnGuard® fresh direct to you from Sunrise, Florida. For over 30 years, Medical Doctors Research has formulated the highest quality nutritional formulas, used by over 2 million people. MDR has been granted several important patents for its innovative formulas that promote youthful vitality, cardiovascular wellness, immune support and overall good health.



Lo Han Melon Helps You Feel Your Best 

MDR infused the OnGuard® formula with Lo Han Kuo. This tasty sweet melon has been prized for its ability to restore good health for centuries by healers in China. Best of all, tradition says those who eat it may live to 100 years of age!



Age-defying Lotus Seeds Boost Your Health!

UCLA scientists found Lotus Seeds could bloom after 1,288 years. They discovered a natural DNA repair enzyme within the seeds that helps them resist the deterioration that comes with normal aging. The exclusive patented Lotus Seed extract is nature’s miracle with restorative nutrients that support healthy longevity!


Big Health Benefits from 2 Small Capsules!

Now is the time to support your cellular defenses. Just take OnGuard® each AM and PM. You'll feel better, stay Healthier, and enjoy life to the fullest. Give your body the immune arsenal you need for general health and well-being.






"I have been taking OnGuard and other MDR formulas every day for over 20 years to stay healthy. They really work! At 86, I am still energetic, healthy and raring to go."




In the News

OnGuard® as seen in the New York Magazine 2020 Fall survival guide!



You have heard her sing the hit song: "To Know Him is To Love Him"
Now, 2-time Academy Award Nominated Songwriter Carol Connors, who
co-wrote the theme from "Rocky" talks about her experience with OnGuard. 





What's the recommended use?

  • Take one OnGuard capsule daily to support your immune system. Take one in the AM and one in the PM for peace of mind if you are rundown or have immune challenges. The moment you suspect you are not feeling well, or or have been exposed in public places, you may increase your dosage to 4 capsules per day (one every 6 hours). 

Is OnGuard safe to take each day?

  • Yes. It should be part of your preventive health supplementation regimen. The biggest advantage of OnGuard is that, unlike a popular herbal immune booster like Echinacea (a ragweed), OnGuard can be taken everyday, for long periods of time - before, during, and after exposure to germs.

*All recommendations are subject to your health care provider’s approval as with any supplement.

If I am on blood thinners, can I take OnGuard?

  • You can take 1-2 capsules a day but do not exceed this dosage. Mushroom extracts may thin the blood, so although this supports healthy circulation for most people, for those taking blood thinners the added anti-coagulation effects must be considered and discussed with your physician.

*All recommendations are subject to your health care provider’s approval as with any supplement.

If I am lactose intolerant can I take OnGuard?

  • Most likely yes. OnGuard® contains Colostrum, a natural milk compound which does contain a very small amount of lactose. Most people who are lactose intolerant take OnGuard® with no difficulty. If you are ALLERGIC to milk or mushrooms do not take OnGuard®.

What's the key to staying healthy?

  • Supporting your immune system every day with a healthy diet, rest, frequent washing your hands, wearing a face mask in close public places and taking OnGuard® are the keys to staying healthy at this time.

What's the Scientific Research?

  • Read a study done by the NCBI (National Center for Biotechnology Information) about the Immune-enhancing effects of Maitake and Shiitake extracts. Click here to read.
  • Read a study done by the NCBI (National Center for Biotechnology Information) about the effect of mushrooms. Click here to read.
  • Read a study done by the NCBI (National Center for Biotechnology Information) about beta glucan. Click here to read.

What are the Ingredients?

  • Colostrum (from Grade A / U.S. Dairy Pasturized Milk)
  • MycoFusion™ Mushroom Complex (MaitakeGold404 (Grifola Frondosa) and Shiitake (Lentinula Edodes) Brown Rice Biomass)
  • Lo Han (Momordica Grosevonia) (Fruit)
  • Sacred Lotus Seed Complex
  • Gelatin
  • Magnesium Stearate
  • Silicon Dioxide


Put Your Immune System OnGuard!

Order Now! Feel Great! Stay Healthy.

or Call MDR at 1-800 637 8227


13 Reviews Hide Reviews Show Reviews

  • 5
    Get your guard on

    Posted by Myrna from Puerto Rico

    I was with my Husband in the hospital for 8 months. I felt very down and without energy and I also started taking MDR Stress Defense and I felt better and with more energy. I have been taking the OnGuard Immune defense for a year and stayed well all year despite everything going on around me! I feel very safe with this Immune defense formula.

  • 5
    It changed my life!

    Posted by Ann

    My friends used to laugh at me because I always seem to catch everything. I was always missing events and work days. I went to a Doctor and he tested my immune system and said it was weaker than average. He recommended the MDR OnGuard formula because he said it helped his other patients. I started taking one with breakfast and one before bed. I started feeling stronger and better. Now I stay healthier than my friends! I will never be without OnGuard. Thank you MDR. OnGuard changed my life!

  • 5
    My Most Important Security

    Posted by Linda Zuker

    Why buy security for everything, when OnGuard offers protection for your most valuable possession - your body.. Since taking OnGuard, my immune system shields me from getting sick all year long. Without good health, everything else you insure will not do what OnGuard can do for you!

  • 5

    Posted by PETER, FL


  • 5
    OnGuard Immune Formula

    Posted by J. Bruno, NJ

    I take the Onguard in the winter months to give me the extra boost for my immune system with the MDR Women Tabs. Because I work with small children, I feel I must stay on top of my health. Ive been taking MDR over 15 years and still happy about my decision for using MDR as part of my wellness care. Thanks MDR

  • 5

    Posted by Karen and Bob, GA

    Onguard does me wonders, especially in the winter time. Having two homes where I eat off one of my property during harvest time and in the winter, I stay fit with my Onguard.

  • 5
    Fantastic product!!

    Posted by B. Foster

    I have never taken a product like this before and it really works. Feeling great and healthier. Love it!!

  • 5

    Posted by Lilly V.

    Thanks to MDR!!! Feeling better then ever since taking this wonderful formula!!

  • 5
    Best Health Formula Ever!!!!

    Posted by Tim, CA

    No doubt this is the best health formula ever. It keeps my immune system strong so I stay healthy. I take one every morning and one capsule before bed. It does not upset my stomach at all. I feel better when I take them. I will NEVER EVER be without OnGuard. Bravo MDR!!!

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