Lectin Shield by Gundry MD Review - Legit or Hype?

By Anthony Dugarte, M.D., C.S.C.S
Updated on: Jan 22, 2020

What is Lectin Shield?

Gundry MD’s claims that their dietary supplement, Lectin Shield, will protect your body from lectin overload.

Lectins are proteins found in both animal and plant products, though they’re most abundant in legumes, fruits, vegetables, and grains. They play a role in many vital biological processes related to cell development and signaling, as well as your immune system.

So why limit their function?

Despite their importance, plant lectins may play a role in the development of conditions like food allergy, inflammatory bowel disease, insulin-dependent diabetes, and rheumatoid arthritis.

There has been discussion regarding meal plans that limit lectin intake, though these diets exclude many common foods and lack strong scientific support. Is there another option for those that wish to avoid the potential harm caused by lectins?

According to Gundry MD, taking two capsules of Lectin Shield twice daily should result in:

  • Reduced appetite and food cravings
  • Increased energy
  • Better digestion and less “Leaky Gut”
  • Cardiovascular support
  • Improved immune system function
  • Reduced Joint Pain
  • Less Brain Fog

They claim that you’ll notice many of these results “within just a few days,” though the most “dramatic” results are likely to become apparent over the course of two to three weeks.

Can one supplement really offer so many benefits?

In this review, we’ll highlight the scientific support for the safety and efficacy of Lectin Shield to help you determine if this is the supplement you’ve been missing.

Who Is Dr. Steven Gundry? Does His Company Make Other Supplements?

Dr. Steven Gundry is a board-certified general surgeon and thoracic cardiovascular surgeon based out of Palm Springs, CA, where he founded The Center for Restorative Medicine Institute.

Here, Dr. Gundry promotes health through diet and lifestyle choices in hopes of helping his patients avoid the surgeries he has performed for over three decades. As he can only see so many patients on a daily basis, he founded Gundry MD to reach as many people as possible.

Dr. Gundry’s focus on diet-based health also lead him to write Dr. Gundry’s Diet Revolution: Turn Off the Genes That Are Killing You and Your Waistline, a three-phase plan that aims to help readers overcome obesity-related diseases.

Gundry MD currently offers over 30 dietary supplements, many of which have been previously reviewed on HighYa.

What Ingredients Are Found in Lectin Shield, and Do They Work?

Lectin Shield’s proposed benefits are thought to be related to its active ingredients. According to the product label, here’s what the supplement contains:

N Acetyl D-Glucosamine (NAG) - 300m

NAG is obtained from shellfish and thought to offer protection from the harmful effects of gluten, though there is minimal support for this, particularly in human subjects.

In a laboratory model, NAG offered protection from the toxic effects of rye, barley, and oat glutens in small intestinal cells obtained from 26 children with gluten intolerance.

Outside of this data, the literature is supporting the use of NAG in this setting is lacking.

Bladderwrack - 200mg

Bladderwrack is a fucose sugar-rich seaweed, also thought to offer protection from gluten.

In a rat study, 575 mg/kg/day of Bladderwrack over 2-weeks was not found to be beneficial as a dietary supplement for weight loss.

Its ability to bind lectins and limit their unwanted effects is unclear.

D-Mannose - 100mg

D-Mannose is a plant sugar that may block lectins, though this benefit has not been demonstrated in substantial scientific investigations with human subjects.

Mannose supplementation in mice on a high-fat diet improved endurance and glucose tolerance, while reducing body weight and body fat.

Okra Fruit - 100mg

Okra is thought to form a gel that can block lectins from attaching to your cells.

In a laboratory study, 0.2 to 2 mg/mL doses of okra extract inhibited the binding of bacteria to stomach cells. Okra may also offer heart health benefits through cholesterol-lowering actions, though this was demonstrated in mice.

Sialic Acid (Mucin) - 100mg

This protein is thought to reduce lectins’ ability to bind to the surface of your digestive tract through its ability to work on cell membranes.

Rats that were injected with 1mg of sialic acid per 50 g body weight for 7-days learned a maze quicker when compared to those treated with glucose.

The brain boosting effects, as well as the other proposed benefits of sialic acid supplementation, have not been demonstrated in human subjects.

Sodium Alginate (Alginic acid) - 100mg

Sodium alginate is thought to bind and remove lectins from your body.

Sodium alginate system formed a gel in the stomachs of rats that served to reduce food intake, body weight and peak blood glucose when compared to control. These findings highlight a potential benefit for supplementation in overweight and obese humans, though research is needed to investigate this possibility.

Vegetable Peptase - 50mg

This enzyme works to break down large protein molecules into smaller ones called peptides.

As this enzyme supports the digestion of the food we consume, supplementation should help avoid symptoms related to undigested food such as bloating, gas, heartburn, and lack of energy.

However, support for the use of vegetable peptidase in this regard is lacking.

Methylsulfonylmethane (MSM) - 50mg

MSM is a naturally occurring sulfur compound thought to offer anti-inflammatory and antioxidant benefits.

Treatment with 3g/day of MSM over 4-weeks in subjects completing resistance training improved blood tests that indicate antioxidant capacity, as well as exercise recovery.

When supplemented along with glucosamine, chondroitin sulfate, guava leaf extract, and vitamin D, 300 mg of MSM improved pain in patients with knee arthritis, though these results were not conclusive.

Larch Arabinogalactan - 50mg

Larch arabinogalactan is a complex carbohydrate from the larch tree (Larix occidentalis) thought to offer anti-microbial and immune boosting benefits.

Those randomized to 4.5g of an larch arabinogalactan had fewer colds over a 3-month span when compared to placebo.

With respect to anti-lectin activity, larch arabinogalactan did not limit lectin activity I a laboratory model.

Is Lectin Shield Safe?

In general, most of Lectin Shield’s ingredients should be well tolerated by most users, with the most common side effects being digestive upset and gassiness/bloating.

These ingredients lack substantial, long-term human studies that investigate various doses in different populations. As most of the available literature is in laboratory or animal models, it is challenging to confidently determine the safety of this product.

Of the ingredients included in Lectin Shield, MSM and larch arabinogalactan have been tested the most in humans. The Food and Drug Administration (FDA) consider MSM to be safe at dosages less than 4845.6 mg/day, while doses up to 4500 mg/day were safe in humans.

Additionally, due to the N Acetyl D-Glucosamine content, you should not take Lectin Shield if you’re allergic to shellfish.

It is safest to speak with your physician before use. Identifying the underlying source for any symptoms you may be experiencing is a good place to start on your road to management.

How Much Does Gundry MD Lectin Shield Cost?

Lectin Shield is available at Gundry MD’s site in the following quantities:

  • 1 Bottle: $49.95 + $4.95 Shipping
  • 3 Bottles: $131.85 + Free Shipping
  • 6 Bottles: $239.70 + Free Shipping

All Gundry MD supplements (more about this next) come with a 90-day money back guarantee, less S&H charges.

In order to request a refund, you’ll need to call Gundry MD customer service at (800) 852-0477.

Lectin Shield is also available through Amazon at $54.25 per bottle. Shipping is currently free, though this supplement is not prime eligible.

Are There Any Alternatives to Lectin Shield?

There are a number of “Lectin Blockers” currently available from different vendors.

Lectin Guard from KaraMD offers a 30-day supply of their formulation for at $29.95 on Amazon. It has bladderwrack, okra fruit, and sodium alginate in common with Lectin Shield, and at comparable doses.

Lectin Lock from Stop Aging Now is yet another option that has an ingredient list almost identical to Lectin Shield, though they offer 400mg of N-Acetyl Glucosamine. They offer multi-bottle savings; 1 bottle/$29.95, 3 bottles/$80.85, and 6 bottles/$149.70.

Another option would be adopting a meal plan that limits lectin intake. Again, it can be challenging to hit daily nutrient requirements by omitting so many foods.

What Are Users Saying About Lectin Shield?

At 4.4 out of 5-stars on over 240 reviews, users seem to report favorable experiences with Lectin Shield.

Over 65% of reviewers rate this supplement at 5-stars. The most satisfied customers cited reduced gas, bloating, diarrhea, and constipation.

Those that rated Lectin Shield 3-stars or less made up about 8% of all reviewers. Unsatisfied customers mainly cited lack of results and expensive pricing for their negative experience, though others mentioned side effects such as diarrhea, constipation, and heartburn.

Gundry MD did seem responsive to those with negative experiences though representatives could do little more than offer a money-back guarantee or suggest seeing a physician.

Will Lectin Shield Provide “Comprehensive Anti-Lectin Health Support”?

Of the many reported benefits from the ingredients included in Lectin Shield, the proposed anti-lectin actions remain unclear. There simply isn’t much support for this action, and most of what the available research is laboratory or animal studies.

This makes determining efficacy challenging as results obtained from animal studies or laboratory models are not necessarily relatable to humans. Promising results in these investigations may highlight the need for more research, however, some of the studies we have reviewed here do not hint at the potential for some of the ingredients.

Also, the doses tested in animals and in the laboratory likely differ from what may be safe and effective in humans. It is therefore hard to draw conclusions from the available research regarding the safety of this supplement.

Though most ingredients are likely safe even at higher doses, be sure to speak to your physician first.

As this is a relatively expensive supplement, particularly if you plan to take it consistently, you may want to look elsewhere in light of the currently available scientific support.


Customer Reviews

Start your review of Lectin Shield:
  • 241 Customer Reviews
  • 90% Recommend This Company
4.4 out of 5
5 star: 65% 4 star: 21% 3 star: 6% 2 star: 2% 1 star: 4%

 Our Promise to You

To safeguard you and ensure helpfulness and relevance, our compliance team manually assess every customer review before it goes live.

We have a zero-tolerance policy for fake reviews, and companies cannot control or alter any reviews at any time.

Sort reviews by:

  • This company is actively collecting reviews from its customers. All reviews submitted are subject to moderation and approval to ensure they meet our Review Guidelines.
  • They do NOT honor their guarantee!

    Overall Experience:

    I ordered this product and they charged me for three times the amount I wanted to order. I figured it's not a big deal if it works. It doesn't. I took this product as directed on the bottle label for over 30 days. It didn't work for me. I asked for a full refund. That's when the trouble started.

    They changed their guarantee on me. Now they say I have to take it a full 90 days, and even then I will only get a refund for the empties. That is not the 90 day no questions asked, no hassle money back guarantee on their website and in their ads. If I have to take it for a full 90 days, the guarantee expires. Don't buy this, save your money and your time for something that work!

    Bottom Line: No, I would not recommend this to a friend

    • Jul 21, 2017

      Company Response from Gundry MD

      Hi David, Aria here with Gundry MD. Thank you for your review of Lectin Shield. I am sorry if you were misinformed in any way about our 90-day money back guarantee. You do not need to take the product for 90 days in order to qualify. If you decide that you do not wish to continue taking the product at any point during the 90 days, you are welcome to return the product. Please send me an email at aria@gundrymd.com so that I can personally assist you with this and make this right for you. Thank you again for reaching out David, I look forward to hearing from you.


  • Dangerous

    • By Lynn West,
    • Key West, FL,
    • Sep 5, 2017
    • Verified Reviewer
    Overall Experience:

    I still cannot believe I fell for this! But for others, here is my experience.

    I ordered one bottle (roughly a month's supply). I started taking the capsules the day I received them, and according to package directions. About a week later I noticed my hairbrush was full of hair, more so than normal; and when washing my hair, it came out in fistfuls! By the end of the month, I had a quart bag of hair to call my own, and less than half the head of hair I started with 30 days before. I showed my doctor the results, and he was incredulous!

    And to add insult to injury, the Lectin Shield didn't make me feel any better than if I hadn't taken them at all! But then, if I hadn't been taking them, I'd still have all that hair on my head instead of in a bag! This is one dangerous scam!

    Bottom Line: No, I would not recommend this to a friend

    • Sep 6, 2017

      Company Response from Gundry MD

      Hi Lynn, I'm Aria from Gundry MD. Thank you so much for letting me know about your situation. I am so sorry to hear that you did not experience the many benefits of Lectin Shield. While many of our customers love Lectin Shield, we do understand that it does not work for everybody. Please keep in mind that it is always very important to consult your primary physician prior to starting any new supplement, especially if any type of side effects occur. I would be more than happy to issue you a full refund just for giving our product a try. Please email me directly at aria@gundrymd.com, and I will begin the refund process immediately. Thank you!


  • Horrible product

    • By Dani May,
    • Bethel, CT,
    • Sep 7, 2017
    • Verified Reviewer
    Overall Experience:

    I took Dr. Gundry's Lectin Shield for about two to three weeks in May 2017. I was taking four pills a day; two with lunch and two with dinner. After about a week to ten days, I started noticing a lot of pain in my middle finger joint, right underneath the nail.

    I did not pay particular attention to the ingredients of Lectin Shield, but since that product was the only new supplement I had added to my daily diet, I looked more closely and noticed that it had shellfish. I had no known allergies to shellfish, but nevertheless, I called and emailed Gundry's company numerous times, asking how much and which shellfish was in the supplement but never got any answers.

    In the meantime, the bones of my joint got more painful and swollen. I am left with a permanently deformed joint thanks to this "doctor's" supplement. About a month later, I had a blood test done to test the IgG for food sensitivities. To my shocking surprise, the test showed that I have an extreme intolerance to clams. I never ever had any food intolerance, and I am wondering if this wonderful product by this so called "doctor" caused this intolerance in my body. My painful and deformed joint reminds me daily of this bad experience.

    DO NOT buy Dr. Gundry's products!

    Bottom Line: No, I would not recommend this to a friend

    • Sep 7, 2017

      Company Response from Gundry MD

      Hi there Dani, Aria from Gundry MD here. Thank you so much for leaving me a review of your experience of Lectin Shield so far. I am so sorry to hear that you did not receive the results you had expected while taking this product. We always suggest that you consult your primary physician before consuming any new product to ensure that you do not experience any interactions with it, especially if any side effects occur. While many of our customers love using Lectin Shield, we do understand that everyone's body is different and it may not work for everyone.

      Yes, as stated on the supplement facts, there is an allergy warning because Lectin Shield does contain shellfish. The N-acetyl D-glucosamine is obtained from the outer shells of shellfish. It is a wheat lectin blocker that is a popular ingredient in joint health supplements. I am so sorry that you had an adverse reaction to this ingredient.

      I want to thank you for giving Lectin Shield an honest try. Please email me directly at aria@gundrymd.com, and I will begin the refund process immediately. Again, I apologize that you had this experience. I look forward to hearing from you.


  • Don't buy or trust this company!

    • By Victor Holton,
    • Indianapolis, IN,
    • Jan 6, 2018
    • Verified Reviewer
    Overall Experience:

    After a high-pressure internet "educational" video, I purchased THREE bottles of this product.

    I got it home and realized that I am allergic to the ingredients in the product! Do you think that the company will stand behind their product video and admit that they failed to mention not to buy if you are allergic to SHELLFISH?

    I can now mail it back at MY EXPENSE. I question the reputation of this allegedly "renowned" physician.

    Bottom Line: No, I would not recommend this to a friend

    • Feb 6, 2018

      Company Response from Gundry MD

      Hi Victor. My name is Aria and I work at Gundry MD. Thank you for taking the time to let us know about your situation. I am so sorry for the confusion that we caused. The ingredients of Lectin Shield are clearly stated on our website www.gundrymd.com, under the "Supplement Facts" section. On this image, you will see the text saying, "Allergy Warning: Contains Crustacean Shellfish." Also, we always suggest that our customers consult their primary physician before starting any new product to ensure that it is right for them. Again, I am so sorry for the miscommunication that we have caused. I would love to issue you a full refund, no need to send anything back! Please email me directly at Aria@Gundrymd.com. I look forward to hearing from you and making this right!


  • Beware, unless you want to lose your money.

    Overall Experience:

    I am not commenting on the product, I don't know if it works, but about their billing practices. I bought a 6 months supply by Visa. I was shocked that they sent and used my Visa details to fund another order also of 12 months supply. I immediately contacted them, but they won't refund my money as they say it has been shipped despite the fact I placed the order at 1 am Eastern Standard Time. Do US workers even work then? Surely there must be laws in the US to protect consumers. They exist in our country.

    So beware, don't trust this company.

    Bottom Line: No, I would not recommend this to a friend

    • May 18, 2018

      Company Response from Gundry MD

      Hi Julia, my name is Aria with Gundry MD. I’m very sorry to hear that this was your experience. Firstly, I want to thank you for trying Lectin Shield. Customer experience is our number one priority, and I want to apologize that your experience was not a reflection of this. It sounds like you accidentally enrolled in our monthly subscription service, but I would like to emphasize that this is a completely optional feature, and I would be more than happy to opt you out of. With that said, I would love to issue you a full refund for the product that you did not intend to order, and no need to send anything back. Please email me at Aria@GundryMD.com to begin the refund process. Thank you!


  • Buyer beware, you will lose your money!

    • By Kiki D.,
    • Sydney, Australia,
    • Jul 26, 2018
    • Verified Reviewer
    Overall Experience:

    I bought a six month supply by using my Visa, as I thought the 90-day return would be ok if the product were a scam, but I was so shocked to see after checkout they used my Visa details to fund another order of 12 months supply! I immediately contacted them, but they won't refund my money as they say it had been shipped, despite the fact I placed the order at 1:00 am Eastern Standard Time. I contacted them as soon as I saw the additional amount on the receipt!

    I pointed this out to them and they took numerous days to reply to further messages that I sent expressing serious concerns, about what they did. And I mentioned a couple of other issues that made the transaction appear completely dodgy, as the information they said in emails contradicted information in the lengthy video. Each email avoided my request to cancel the order and gave pre-rehearsed marketing type answers. This is ambush marketing and theft.

    Bottom Line: No, I would not recommend this to a friend


  • Three days of agony

    • By Bernice W.,
    • Michigan,
    • Jan 21, 2019
    • Verified Reviewer
    Overall Experience:

    I received my order of Lectin Shield. Instead of two pills, I've taken one pill during my meals. The first day I took one pill with supper. The next morning I experienced intestinal distress and diarrhea. Since I have digestive issues, I thought maybe it just takes time. Second day I took two capsules and felt terrible the next day. But I still took one pill with lunch and one pill with supper. My abdomen swelled up and I felt like I could puke. I went to bed with a bucket next to my bed in case I threw up. This morning my guts still hurt and I had mild diarrhea! This is not the results I had hoped for. I'm not allergic to shellfish. I am laying around with a painful gut and getting nothing done.

    Bottom Line: No, I would not recommend this to a friend

    • Jan 22, 2019

      Company Response from Gundry MD

      Hi Bernice, my name is Aria with Gundry MD. I'm very sorry to hear that this was your experience with Lectin Shield! This sounds like a horrible experience. I want to assure you that this is not a typical side effect of taking Lectin Shield. We understand that everybody is different so we always ask that our customers consult their physician prior to beginning any new supplement. Please email me at aria@gundrymd.com and I will immediately refund your order.


  • Bad product for thyroid issues and refund is flawed

    • By Lucretia B.,
    • Collierville, TN,
    • Feb 3, 2019
    • Verified Reviewer
    Overall Experience:

    This product causes your stomach to swell with really bad GI problems. Also, I bought six bottles and just halfway completed the second bottle thinking GI problems would stop...didn’t happen! So I tried to get a refund for the other four bottles and was told it was beyond 90 days. Advice, buy only one bottle due to the flawed refund, even if you save with quantity. They say take this product for at least, yes more than, 30 days or more to truly see results. I also broke out in a rash. I’m not allergic to anything based on a recent medical evaluation. I am a very overweight person, so maybe for those with only less than 30 or so lbs it works, who knows. Not recommended either way, especially the refund being so flawed.

    Bottom Line: No, I would not recommend this to a friend

    • Feb 4, 2019

      Company Response from Gundry MD

      Hi Lucretia, my name is Aria with Gundry MD. I'm very sorry to hear that you had this experience while taking Lectin Shield. Those are not typical side effects. As always, we ask that you consult your physician prior to starting any new supplements to ensure that it is right for you. In regards to the refund, please email me at aria@gundrymd.com and I'd be happy to issue you a full refund regardless of how much time has passed.


  • Not working for me

    • By Terrie M.,
    • St. Louis, MO,
    • Aug 7, 2019
    • Verified Reviewer
    Overall Experience:

    I really wanted this to help with my gas and bloating but I’ve been taking it about a month and it’s not helped at all. Nothing. I have two opened bottled and two unopened bottles I’m stuck with because I was so hopeful for this product.

    Bottom Line: No, I would not recommend this to a friend

    • Aug 8, 2019

      Company Response from Gundry MD

      Terrie, I want to thank you for giving these products a try but I'm sorry to hear that they were not the right fit for you. Please email me personally at aria@gundrymd.com and I can take care of your order for you.


  • Did not work for me

    • By Leon H.,
    • Arizona,
    • Aug 17, 2019
    • Verified Reviewer
    Overall Experience:

    Based on radio advertising I decided to give Lectin Shield a try. I took it religiously for 75 days per required dosage. In the first 30 days, I got diarrhea. But I persisted. I noticed no notable difference in my health and my energy level remained the same, but at times I felt I wasn't as active. After 2 and a half months, it was time for a refund. I received my refund, no questions asked. Too bad it didn't work for me.

    Bottom Line: No, I would not recommend this to a friend

    • Aug 19, 2019

      Company Response from Gundry MD

      Hi Leon, thank you for giving Lectin Shield a try! I'm sorry to read that it wasn't the right fit for you, but it's great that you were able to take advantage of our money-back guarantee. Please don't hesitate to reach out to me personally at aria@gundrymd.com with any questions or concerns in the future.


  • System glitch

    Overall Experience:

    I logged in searching for Lectin Shield, looking for the best deal. It was a single bottle for $79.95, but I clicked the button at the top for deals for new customers, chose the 6-bottle price at what appeared to be $37.45 each. I had just listened to the video and wanted to try it. I went through the process and made the purchase.

    I had to tell the system "NO" to 4-5 additional products, including Vital Reds as I already take a 'Feds' product I like. I discovered at the end of the order that I actually purchased Vital Reds. Had I not scrolled down and looked at the receipt, I would have received Vital Reds in a few days, and probably would have had to pay to ship them back.

    I called immediately and they canceled the order. I decided not to try the product after all!

    Bottom Line: No, I would not recommend this to a friend

    • Feb 7, 2018

      Company Response from Gundry MD

      Hi Sharalyn, I'm Aria from Gundry MD. Thank you so much for taking the time to reach out to me regarding your ordering experience. I am so sorry about the glitch that occurred while you were ordering Lectin Shield. Thank you for bringing this to my attention as I take these comments seriously, so I will do my best to make any changes necessary to avoid this issue in the future. I am happy to hear that our customer service department was able to assist you with canceling the order. If you have any other questions or concerns at all, please feel free to email me directly at Aria@gundrymd.com. Again, I am so sorry for the frustration and inconvenience that occurred.


Showing 1-11 of 241

Write a Review for Lectin Shield!

Share your experience to help others discover great products!

Write a Review
Lectin Shield