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A Comparison of 20 Equine Ulcer Supplements

Updated: Jun 19

Are you overwhelmed by the scope and breadth of gastric ulcer treatments and preventions on the marketplace today? In this article, I organize 20 equine products into categories depending on their marketing claims, ingredients, and cost. At On Course Equine Nutrition, the goal is to customize your equine ulcer supplementation to the specific location and severity of your horse's GI tract dystopia and match an affordable product to your horse's symptoms. First bit of advice- don't trust the reviews. Trust the facts and put them to the test with a timeline!

The Optimist and the Pessimist

I've been thinking long and hard about how best to summarize the universe of "equine ulcer supplements", and it's not easy. The optimist in me would love to offer you a neat little summary, but the pessimist in me knows that we're in the wrong category of supplements for that. The magic number seems to be 8; 8 categories of marketing claims, 8 categories of ulcer supplement ingredients, and 8 steps to finding your perfect equine ulcer prevention. However, please, please, please read "Before Purchasing That Ulcer Supplement, Do This..." by OCEN, LLC (April 2023). There are three steps to preventing gastric ulcers that MUST be explored before a supplement has a chance to be effective.

The optimist sitting on one of my shoulders wants you to know that many ingredients used in these products add real value to your horse's health. I've read the research on ingredients that buffer the pH of the stomach, provide energy to epithelial tissue, and help the immune system do its job. I regularly recommend many of these products depending on the specific nutrition goals that my clients and I are trying to address. After writing this comparison, there are several more that I will add to my recommendation list.

However, the pessimist sitting on my other shoulder also wants you to know that there are a lot of supplement companies that are far better marketing agents than horse health experts. So, in order to a) keep this article from being an hour long to read and b) keep my job and my sanity, I have refrained from arguing product efficacy. It is NOT the goal of this article to tell you if a product works or not. That is the job of the supplement company. I've wasted too many hours of my life searching for proof of efficacy that rarely exists in the equine supplement industry. I have, however, put an *asterisks next to the supplements that have supplied you with some research on their website. The quality of that research is not discussed. For more information about choosing a supplement without research to back it up, read "How to Trial a New Supplement" by OCEN, LLC (June 2021).

This article and charts provided are solely comparisons of marketing claims, ingredients, and cost. My absolute greatest wish is that this article INSPIRES you to ask more questions! I hope that you take your top 3 favorite products in this article and then ask those companies a lot more questions such as...
  1. What is your return policy? Can I return this product if I do not see changes in my horse's symptoms?

  2. How does this product work, and how do I know that it's working?

  3. Can the company send 1-3 peer reviewed articles that support the efficacy of your product's primary ingredients in horses?

  4. Does the amount of ingredient in the product match the amount of ingredient used in the research?

  5. What are the credentials of your supplement's primary creator?

  6. What 3rd party oversight helps guarantee the consistency, safety and quality of your product every batch?

What Are the Marketing Claims Telling Us?

We'll start with marketing claims as they attract our attention and direct our expectations. You are likely reading this article because a) your horse has ulcers somewhere in the digestive tract and you want to get rid of them, or b) you want to prevent ulcers anywhere in the digestive tract for all of your time with this horse. However, when you type in "equine gastric ulcers" on Google and then read the marketing claims for the supplements at the top of your search, you realize that these products are going about preventing ulcers in round-about ways. Creating a "healthy balanced microbiome", preventing "abnormal manure", and reducing "free radical formation" somehow circles back around to fewer ulcers. We think...or maybe we are just assuming!

Marketing claims for equine ulcer supplements are rarely specific and there is good reason for this too. Ultimately, remember, we are trying to prevent ulceration of the equine digestive tract, but only pharmaceuticals are technically allowed to claim direct affect on a disease. Fewer than half of the supplements that I reviewed made a direct claim to prevent or treat ulcers in the gastrointestinal tract of the horse. Ulcer prevention was mostly implied which is proper for a nutraceutical, but it begs us to ask more questions and dig deeper. Claims such as Silver Lining Herb's "supporting general digestive issues" on the webpage for their GUT product is about as vague as it can get. What digestive issues? What does "support" mean? Why would we want to support these issues? With such vague notions of aid, how are we supposed to choose the right product to fit our horse's specific symptoms and nutrition goals?

Claims such as creating a "healthy mucosal barrier", "healthy gastric acid levels", and "healthy levels of mucosal inflammation" found on Platinum Performance's page for Gastric Support are certainly helping us get closer to our goals, but HOW do the ingredients accomplish these things? How long do they last? Where in the 70 feet of digestive organs are they working? How do we even know that these modes of action lead to less ulcers in most horses? (More questions to ask your favorite companies!) We know some of the answers to some ingredients used in some gastric ulcer prevention, but not MOST of them and certainly not all of them. I counted over 50 unique ingredients listed on 20 product labels and that does not include the "proprietary blends" and the individual species of microorganisms.

I have summarized the marketing claims in a list below organized into 8 "modes of action". What you need to do is consider your horse's specific and unique symptoms and try as best you can to match them to the marketing claims of the company. Then, have realistic expectations whether or not the product is actually going to treat or prevent ulcers considering your horse's risk factors (i.e. living situation, amount of riding/travel, history, ect).

  1. Affecting the immune system in a positive way

  2. Mitigating the effects of stress and poor management

  3. Creating a more effective barrier against pathogens in the lining of the digestive system

  4. Decreasing inflammation anywhere in the digestive tract

  5. Buffering the pH of the stomach

  6. Changing the ecology of the microbiome

  7. Improving digestibility of total diet and nutrient extractions

  8. Promoting good gut motility

Are you confused yet? Just wait for the ingredients list!

8 Ingredient Categories of Ulcer Supplements

One of the most difficult parts of comparing equine gastric ulcer supplements is the extreme range of ingredients that you will find in them. I counted more than 50 different active ingredients (not counting the multiple species of bacteria or the "proprietary" ingredients). I summarized ingredients from 20 supplements into 8 different categories. As you will see in the comparison chart below, I have very simply marked each ingredient category as a YES or NO.

  1. Minerals: Most common include sodium bicarbonate, calcium bicarbonate, marine derived calcium, aluminum phosphate, and magnesium. The calcium and aluminum compounds are supposed to be acid buffering agents.

  2. Vitamins: riboflavin (B2), thiamine (B1), and vitamins C, A, and E. It's unclear to me how these directly or indirectly affect ulcers in horses.

  3. Herbals: Most common was slippery elm bark followed by milk thistle seed powder, marshmallow root powder, licorice root powder, aloe vera powder, psyllium husk powder, red algae, rose hips, yarrow, chamomile, plantain, fenugreek, papaya, turkey tail and lion's mane mushroom species, and more. The best I could tell from representative ramblings is that these ingredients are generally "soothing" and hope to mitigate inflammation in the GI tract. Other plant based ingredients such as psyllium husk powder and red algae have other functions.

  4. Amino Acids: L-glutamine was very common ingredient to "feed" the epithelial tissue of the GI tract. Less common were methionine and threonine.

  5. Yeast and their Byproducts: Lots of mannanoligosaccharides, saccharomyces cerevisiae or saccharomyces boulardii. These ingredients have a positive affect on the immune system.

  6. Bacteria: Species of Bacillus, Lactobacillus, Enterococcus have the potential to positively effect the microbiome.

  7. Enzymes: Protease, amylase, and cellulase appear in the Arenus Assure Guard Gold and are presumably placed in the horse's GI tract to improve nutrient extraction.

  8. Other: Ingredients like collagen, bovine colostrum, hyaluronic acid, beta-glucan do not fit neatly into the other categories.

Mind you that each equine ulcer supplement will have a vastly different blends of these ingredients at wildly different amounts making them nearly impossible to compare fairly. The ingredients lists all depend on what the supplement creator has been exposed to, their education, their cultural beliefs, ingredient availability, and profit margin goals. It's just as likely that your supplement choice will match the creator's cultural beliefs rather than research results.

Considering Cost

If we narrow our comparison focus to objective cost, there is also a great range. You can spend as little as $0.49 per day to feed Natures Pet Supply GastroElm Plus and $0.56 per serving to feed Purina Outlast, or you could spend as much as $8.63 per day for 2 scoops of the Platinum Gastric Support. That's $179 per year compared to $3,150 per year. Other high cost products included Kentucky Performance Products Neigh-Lox for $5.21 per day (16 oz recommended daily serving) and Arenus Assure Guard Gold for $4.71 per day (132 grams serving). Do you get what you pay for in this supplement category? I honestly don't believe that statement is applicable in this case. Again, it depends on your specific nutrition goals.

The mean daily serving cost of all 20 products was $2.66 which is $971 per year (a.k.a. 2 horse show entries). If you are preventing ulcers from reoccurring, you might want to spend more. If you are trying to prevent ulcers for the first time, you might want to spend less or nothing at all. However, if you are currently treating active ulcers, I suggest talking to your vet about pharmaceuticals and then circle back around to preventing reoccurrence.

How to Customize Your Equine Ulcer Supplementation

The goal at On Course Equine Nutrition is to make smart supplement choices based on your unique, specific nutrition goals and then put them to the test with a timeline. During your first private consultation, you will be asked the following questions which will lead us to the appropriate equine ulcer supplement!

  1. Are you treating or preventing ulcers?

  2. Where is the problem in the digestive tract?

  3. How severe is the problem?

  4. Which marketing claim best addresses your specific nutrition goal?

  5. Which category of supplements has the most research?

  6. What is your annual budget for a supplement? How important is cost to you?

  7. What is readily available or easy to get?

  8. Will your horse eat it?


I want to start this summary by saying that I'm not against any of these products. There's not one that I'm a hard NO on. I regularly recommend several of the products listed in the comparison chart. However, I have to admit that I do not feed any of these 20 products daily to my own horses. I've scoped two horses in the last 2 years and neither of them had ulcers either. I believe strongly in great management to prevent disease. I NEVER recommend a supplement without first asking the following questions; 1) how is forage type, quantity, and quality contributing to the ulcers, 2) what stressors can we better manage in the horse, and 3) what already exists in the horse's diet so that we don't duplicate? For example, there are a half a dozen ingredients in the above list that are already in the feed/supplement products that I do feed daily. If you don't have clear answers to the above 3 questions, then an equine nutritionist could be the first step. You can easily spend $1,000/year feeding the wrong supplement countered by poor management, so get help!

When I step back from the comparison chart and think about what we have learned, I'm struck by the lack of agreement about how to prevent ulcers in horses. It makes you wonder if we shouldn't just throw the entire metaphorical kitchen sink at our horses and hope for the best. But then, I look at the products with peer-reviewed research behind them such as Purina's Outlast product, and it's one of the most simple and cost-effective products on the market. Let me be clear one more time. NONE of these products are going to completely prevent or treat gastric ulcers for all of your horses every time. So, shop smart, be critical, and ask more questions!


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