OnGuard Immune Defense Capsules

Take OnGuard® and put your immune system ONGUARD® 24/7!

OnGuard® Immune Defense

Enhance your Immune System Feel Better. Stay Healthier Year Round!

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Put Your Immune System OnGuard® 24/7!

How good is your immune system?

Many things can weaken your immunity.

  • If you don't eat right
  • Don't get enough rest
  • Suffer with certain medical conditions
  • Are over 65+

No matter how healthy you are, with advancing age your immune system declines. Worse yet, if you were exposed to some pathogens when you were young, they may remain with you, waiting to resurface when you get rundown or weakened by stress.

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!

It contains special compounds from nature that science has shown to benefit the immune system and improve health. Unlike products people take when they don't feel well, OnGuard® was developed to be taken every day for prevention!

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. If someone coughs or sneezes, germs can float in the air invisibly waiting to find their next victim.

Crowded areas increase your risks of exposure to deadly germs. When you least expect it, you could be exposed to deadly bacteria and viruses. You need to be ONGUARD®!







Cruise Ships






Use OnGuard® daily to support your
immune defenses!


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.


Proven, patented mushroom extract enhances immune cell activity and increases cell defenses.


Transfers protective antibodies & 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 & longevity.

Lotus Seeds

Longest living seeds (1288 years) revitalize your health. Supplies protective nutrients and antioxidants.

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!   It's one of the reasons why so many people enjoy great health from taking OnGuard® every day.

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.

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.

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 the Colostrum is free of: Artificial Hormones, Antibiotics, Pesticides, GMO, and BSE.

This Melon helps you to Feel Your Best Each Day

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 1288 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.

Put your Immune System OnGuard®!

Taken on a daily basis the formula can help support healthy immune function and general health and well-being.

Satisfaction Guaranteed

Put OnGuard® to the Test! If you are not thrilled with the increase in health, stamina and wellness, just send back the empty bottle for a full refund!

30 Day Money Back Guaranteed

Proven by the Test of Time

This TV show aired over a decade ago! MDR was decades ahead and our customers have reaped the health benefits! Now its your chance to be healthier with OnGuard®!
MDR-leaders in nutrition science for 30 years.
Note: Special offers in videos subject to change.


Frequently Asked Questions

What's the recommended use?

Take one OnGuard® capsule daily to support your immune system. Increase to 1 AM and 1 PM for peace of mind if you tend to be rundown or have immune challenges. The moment you suspect you are not feeling right and have been exposed to sick people or crowded public places, you may increase your dosage as high as 4 capsules per day, two AM and two PM or 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

"I have been taking OnGuard and other MDR products every day for over 20 years to stay healthy. They really work! At 85, I am still energetic and healthy and raring to go."



Listen to what our customers are saying

"My Most Important Security"

"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! "


29 JUN 2020

"My favorite MDR product. Better than 5 stars! A winner!"

"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. I've been taking MDR over 15 years and still happy about my decision for using MDR as part of my wellness care. Thanks MDR"


3 AUG 2020

"I fly a lot and can't live without OnGuard!"

"I fly alot and know there is a risk in airplanes. With my busy lifestyle I can't afford any down time. My stewardess friend told me about OnGuard and how she stays healthy despite all the trips she takes. Wow, what a difference OnGuard makes. Great product!"


4 MAY 2020

Start your Journey to
Better Health!

You can't afford not to take advantage of this important protective health formula. Try OnGuard® and see for yourself how great it is to enjoy robust good health.

In the News

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

Put Your Immune System OnGuard® Now!
        Order Now! Feel Great! Stay Healthy.
        Click below or Call MDR at 1-800 637 8227


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Put your Immune System OnGuard® 24/7!

Taken on a daily basis the formula can help support healthy immune function, general health and well-being.

Satisfaction Guaranteed!