Scientific and Equine Consultant

How not to get fooled by equine supplement marketing tricks by Dr David Marlin

I get lots of emails and messages and comments about how confusing people find the terminology and layout of supplement labels and how they struggle to understand or work out how much their horse is actually getting and to be able to compare supplements on the same basis. So from having answered these questions many times, I thought a simple to understand but comprehensive guide for horse owners might be helpful.

Active ingredients

There is no legislation that currently requires supplement companies to identify active from inactive ingredients in a supplement. However, good labels will clearly show the amount of active ingredients delivered for a specified dose e.g.

Active Ingredient Levels per 54g (500kg Horse, Maintenance feeding rate) delivers: MSM 6.5g; Glucosamine HCl; 10g; Chondroitin Sulphate 4.1g; Vitamin C 5.0g; DHA 1.9g; EPA 1.0g (Total Omega 3 2.9g); Hyaluronic Acid (HA) 150mg.


Active ingredients at Ineffective Levels

A fairly common marketing trick is to include what is considered by many owners an important active ingredient but at very low levels. Often such ingredients are expensive ones. A good example here is chondroitin sulphate in joint supplements. Chondroitin sulphate is expensive but at the same time needs to be included at high levels for effectiveness.

  • Chondroitin sulphate     20mg                                     …..Ineffective level

  • Chondroitin sulphate     2g                                           …..effective level

In the example above, if you are looking for chondroitin sulphate on a label then of course you see it. 2g is equal to 2000mg so the effective supplement contains 100x more active ingredient. You may not be aware that 20mg will have no effect whatsoever.

This trick is also often combined with the Units trick Look at the two examples below:

  • Chondroitin sulphate     20,000ug                              …..Attempt to mislead

  • Chondroitin sulphate     2g                                           …..Genuine

20,000ug = 20,000 ÷ 1000 = 20mg

2g = 2 x 1000 = 2000mg

2000mg ÷ 20mg = 100

There is 100x more chondroitin sulphate in 2g than there is in 20,000ug but 20,000ug looks more impressive on a label than 2g.


Active Ingredients Do Not Meet Label Claim

As a consumer you would expect that the amount of an active ingredient stated on the label will be the amount in the supplement? Sadly this has been shown to often not be the case. A published study evaluating human joint supplements found that only five out of 32 products tested met the label claim for chondroitin sulfate. A similar analysis of equine joint health supplements also showed that 9 out of 23 glucosamine products failed to meet label claim, with four products having less than 30% of the amount on the label! How can you know? You can’t, unless you send a sample to a laboratory and have the level measured. This really comes down to trust and purchasing supplements from reputable companies.


Analysis/Analytical Constituents

Under EU law companies are required to list on their labels the following information as a percentage of the finished product (% – equivalent to g (grams) per 100g of product): Crude protein,

Crude oils and fats, Crude ash, Crude fibre, Sodium. Typically this might look something like this:

  • Crude protein 25%

  • Crude oils and fats 5%

  • Crude ash 17%

  • Crude fibre 8%

  • Sodium 0.1%

Some companies also list additional information on moisture, starch and sugars but there is currently no requirement to do so.

The Analysis information is not really that relevant for supplements but is obviously essential for feeds. For example, if a supplement is 25% protein people may be worried that it will provide too much protein. However, even if fed at 100g per day this would mean your horse was still only getting 100g * 25%/100% = 25g of protein from the supplement. A 500kg horse not in work requires around 600g of crude protein per day so 25g represents a very small fraction – around 4%.



Whilst not directly related to misleading marketing, many substances that will result in a positive drug test contaminate feed and supplement raw materials. These are referred to as Naturally Occurring Prohibited Substances (NOPS). Companies that are part of the BETA NOPS scheme are part of a programme that regularly tests for these contaminants in individual ingredients and finished product. There is also an early warning scheme that alerts BETA NOPS scheme members to ingredients in the supply chain which may be contaminated. If you are competing in ANY affiliated competitions or racing then you are taking a huge risk buying from companies that are not BETA NOPS members. You can check to see if your supplement supplier is a member here: http://www.beta-uk.org/pages/feed-safety/beta-nops-scheme.php#companies.



A term often seen on supplement labels is “bioavailable”. There may be 10g of an ingredient in a supplement but the amount taken up into the circulation may only be a fraction of that. If it’s all taken up then its 100% or highly bioavailable e.g. sodium. If only a small fraction is taken up then it has low bioavailability. High bioavailability is desirable as this reduces wastage – ingredients that simply pass through the GI tract and end up in droppings. Some different forms of ingredients are more bioavailable than others. Magnesium in magnesium aspartate or magnesium chloride is much more bioavailable than magnesium in magnesium oxide; calcium in calcium gluconate is much more bioavailable than calcium in calcium carbonate (limestone); Vitamin C is much more bioavailable as calcium ascorbyl monophosphate than as L-ascorbic acid. Creatine is an example of a supplement with NO or 0% bioavailability in horses. Horses do not absorb creatine so you may be surprised to see it in many equine muscle building supplements!


Carriers, Fillers, Bases and “Bulking Agents”

Many supplement companies advertise that their supplements are free from “carriers, fillers and bulking agents” as if including these is always a bad thing for customers. The implication is that a carrier is a cheap and nasty ingredient designed to fool the customer into thinking they are getting a good deal. Of course if a supplement was 99% inactive ingredients (e.g. wheatflour) and only 1% active ingredient then this is probably a bad thing but this would be rare. Carriers are most commonly included for the following technological reasons (i.e. reasons that improve the product):

  1. Palatability – some active ingredients included at the optimal level don’t taste very nice to horses

  2. Stability – Some ingredients used in equine feed supplements may normally have relatively short shelf life. Carriers can extend the shelf life of certain ingredients in a number of ways.

  3. Distribution – To make sure that each scoop contains the same amount of actives and avoid settling

  4. Ease of feeding – To avoid owners having to feed ¾ of 2/3rds of a scoop a carrier may be added to round up to a convenient whole scoop

  5. Functionality/Efficacy – To enhance the activity of another active ingredient. A good example here is the combination of a source of carbohydrate (such as dextrose) when feeding concentrated protein.

  6. Alternative Delivery / Balancing – In many instances a supplement may need certain ingredients balancing. For example, a supplement may require the addition of calcium to balance magnesium.

  7. Safety – if the amount of a supplement to be fed was very small e.g. a few mg per day, then it would be very easy to overdose. With a carrier and a larger scoop size the error in measuring is less. An example would be feeding biotin.

I have written in detail about this topic elsewhere (http://davidmarlin.co.uk/portfolio/the-truth-about-fillers-and-bulking-agents-in-equine-supplements/).



Under EU law companies are required to list on their labels in this section all the actual individual raw ingredients in a product in descending order. If a label showed the following:

  • Composition: Wheat flour, calcium carbonate, sodium chloride, mint.

…we cannot tell from the label the amounts of each ingredient. For example, it could be equal amounts of each or 99% wheat flour. However, it should be that wheat flour is the highest ingredient, followed by calcium carbonate, sodium chloride and mint. The composition information does not tell you how much of each ingredient is in the product but can be useful if you have a horse that is sensitive or allergic to particular ingredients as ALL ingredients MUST be listed.


Feed Additives (often just listed as additives)

Feed additives are products used in animal nutrition for purposes of improving the quality of feed and the quality of food from animal origin, or to improve the animals’ performance and health, e.g. providing enhanced digestibility of the feed materials. Feed additives may not be put on the market unless authorisation has been given following a scientific evaluation demonstrating that the additive has no harmful effects, on human and animal health and on the environment. Any ingredient that is considered a “Feed Additive” under EU law and included in the EU Register of Feed Additives must be listed separately on the label. Many common ingredients have been listed as feed additives and these will have a specific code. So for example Vitamin B1 (Thiamine) has the code 3a820, Vitamin D has the code E671 and Vitamin E has the code 3a700.

Supplements including any feed additives must show the level of the additive per kg of the finished product along with its code in a separate area of the label. For example:

  • Additives (per kg)

  • Vitamin E (3a700)                                                             50,000IU

  • Saccharomyces cerevisiae (NCYC Sc47 4b1702)        1.0 x 10^10 CFU

Feeding Instructions

Most owners are familiar with the concept of loading “doses” or feeding rates and maintenance feeding rates, especially when it comes to joint supplements, hindgut balancers and respiratory supplements. Most commonly the loading dose is around 2x the maintenance feeding rate. However more recently the use of loading, normal/standard maintenance and low/lower maintenance has crept in. So far I have yet to see any evidence from any scientific studies to support the use of these different feeding rates and my suspicion is that it is a marketing exercise. Obviously feeding at a lower rate reduces cost and makes the product last longer: things that will be attractive to owners. However, if feeding 50g is effective, why would feeding 25g be equally as effective? It won’t.


Illegal Ingredients

Any ingredient used in a feed or supplement for horses in the EU must be listed in the Feed Materials Register or the EU Register of Feed Additives. This is to ensure that any ingredients used are safe to be fed to horses and pose no risk to owners. Two common ingredients which are widely but illegally used in feed supplements in the UK are the amino acid L-Glutamine and live bacteria products for horses. Live bacteria are of particular concern as currently there are NO live bacterial species registered for use as probiotics in horses and any company using them is in flagrant breach of EU law and risking the health of horses. In addition, live yeasts cannot be used in supplements or feeds for horses other than the ones that are listed on the Register of Feed Additives.


Individual/Personalised/Bespoke Supplements

Sounds great doesn’t it? A supplement specifically formulated for your horses precise needs! Whilst I may make individual supplements for sick horses not responding to normal nutritional management, this is extremely expensive due to time and small volume production. In addition, for true individualised nutrition we need more than a short history. My “basic” nutritional history form contains 54 questions! For individually designed supplements we would be looking for analysis of each feed component (e.g. hay, forage, possibly even water), precise measurements of feed intake, faecal analysis, urine analysis, blood analysis, etc. So whilst it sounds great in principle I think you will struggle to find any equine nutritionist who believes that this can be done effectively based on answering a few questions in an online form!



I’ve covered this one on detail elsewhere as it can be very confusing and some companies use clever tricks when it comes to percentages to mislead consumers (http://davidmarlin.co.uk/portfolio/dont-get-fooled-by-equine-supplement-marketing-dr-david-marlin/) As an example:

  • Supplement A: 50% glucosamine; Daily total dose of supplement fed = 20g; Amount of glucosamine per day = 20g * 50%/100 = 5g

  • Supplement B: 20% glucosamine; Daily total dose of supplement fed = 50g; Amount of glucosamine per day = 50g * 20%/100% = 10g

Supplement B with the LOWER % glucosamine gives your horse TWICE as much glucosamine per day.

Bottom line – NEVER trust a company that is trying to market a supplement to you based on the percentage of ingredients. Why? Because percentage on its own tells you nothing about the dose of active ingredient your horse will get.


Quality of Ingredients

Two different supplements may both contain the same amount of an active ingredient. How do you judge if they are the same or which one is better? This is one of the most difficult aspects of comparing different supplements. This is particularly an issue with joint supplements where the individual raw materials such as HA and Chondroitin sulphate are very expensive. There is not just one type of each ingredient available to supplement manufacturers there are literally hundreds ranging from very cheap low quality to extremely expensive pharmaceutical grade for injection into the bloodstream. How do you know what quality is in your supplement? For Chondroitin sulphate the best guidance is look for the term “low molecular weight” as this affects absorption. However, you may want to ask the company directly what the molecular weight is. The only real option is to buy from companies that you trust. In this respect the less expensive supplements are also very unlikely to be using high quality raw materials.



The amount of an ingredient in a supplement is given in three common forms:

  • For most ingredients it is simply WEIGHT

  • For enzymes it can be WEIGHT but may also be ACTIVITY

  • For live yeasts it is CFU (colony forming units)

  • Weight – In the metric system all units are easily converted.

1kg = 1,000g = 100,000mg = 100,000,000ug

1g = 1,000mg = 100,000ug

1mg = 1,000ug

The common convention in science is to use the weight units that you avoid using lots of decimal places or lots of large numbers with lots of 0’s. So rather than say 10,000mg of glucosamine we should say 10g.

Activity – Instead of how much of something is included in a supplement by weight, for ingredients such as enzymes and Vitamins, the amount present may be shown as “activity”. This is common for Vitamin E which can shown as the weight in mg or as IU, which stands for International Units. The two are related but slightly different. The weight is the same for different forms of Vitamin E but the IU is how it works in the body or the activity. So for example, for 1 mg of synthetic Vitamin E the biological activity in the body would be equivalent to around 1.5 IU. Feeding 100mg of Vitamin E would therefore give you 150 IU of Vitamin E activity. You may see Vitamin E on labels especially in the Additives listing as 50,000IU or 50KIU (K = 1000; 50 x 1000 = 50,000IU). So 50,000IU and 50KIU are the same.

CFU – Colony Forming Units. This is the way that the amount of live ingredients in a product are described. In equine feed supplements this is most commonly for probiotic yeasts. The CFU is calculated by taking a sample of the product and or the raw ingredient and growing it to see how many colonies are formed. A colony is a group of yeasts or bacteria of the same species growing together. The CFU in a product is usually shown as CFU per g (when referring to how much your horse will get in a scoop or daily dose) or per kg of finished product (when in the Additives information section on the label). These are BIG numbers. A small amount of live yeast will produce a lot of colonies. But this is what you want if you are feeding a horse. A few g of live yeast may contain millions of CFU but still have no effect in a huge hindgut. Below is an example of CFU for the yeast Saccharomyces cerevisiae

  • 5 x 10^7 CFU per kg = 5 x 10 x 10 x 10 x 10 x 10 x 10 x 10 (7 lots of 10) = 50,000,000 (50 million) CFU

  • If you feed 10g then you will be giving your horse 50 million CFU ÷ 1000g (1kg) x 10g = 500,000 CFU

N.B. If the yeast in a supplement is DEAD as opposed to LIVE, then the yeast will just be listed by weight or in the ingredient list even without a weight and there will be no “CFU” listed on the label. Dead yeast can act as a prebiotic but only live yeast can act as a probiotic.



  • Active ingredients – No requirement to show levels but good labels will clearly show the amount of each ingredient per typical dose.

  • Active ingredients at Ineffective Levels – Included on the label but present in the supplement at very low and ineffective levels. Made to look better than it is by showing as 1000ug instead of 1mg or 0.001g.

  • Analysis/Analytical Constituents – As supplements are fed in relatively small amount even if starch is high as a % the total amount the horse gets (weight) will be very small.

  • BETA NOPS – essential if you are competing affiliated or racing!

  • Bioavailability – many ingredients used in equine supplements are not absorbed at all (e.g. creatine) or poorly absorbed (e.g. L-ascorbic acid).

  • Carriers, Fillers, Bases and “Bulking Agents” – Not always a bad thing to have these in a product as they have important technological functions such as increasing shelf life, preserving active ingredients, improving palatability.

  • Composition – Ingredients should be listed in descending order.

  • Feed Additives (often just listed as additives) – Must be listed individually in a separate area of the label (e.g. Vitamin E).

  • Feeding Instructions – confusing feeding instructions e.g. Lower maintenance dose, maintenance dose, loading dose, high workload dose.

  • Illegal Ingredients – Inclusion of banned ingredients such as glutamine or live bacteria!

  • Individual/Personalised/Bespoke Supplements – Sounds great but requires a large amount of accurate information and testing to be done effectively.

  • Percentage – Misleading marketing. NEVER buy on %. The key thing is amount – i.e. the weight, activity or CFU of an ingredient in a daily dose

  • Quality of Ingredients – A hard one for owners to judge. You have to trust the company. Cheap supplements = cheap ingredients = likely less effective.

  • Units – A common trick is to list ingredients as 1000ug rather than 1mg as the big number looks better!


Date: April 21, 2017