Check four things in this order: exact milligrams per serving for every active ingredient, the chemical form of each ingredient (HCl vs sulfate, chelated vs oxide), the serving size in grams, and whether dosing instructions adjust by horse weight. If any of these are missing or hidden behind a “proprietary blend,” that’s a red flag.
Most horse owners pick supplements by brand name, barn recommendations, or whatever their vet stocks. The label is an afterthought. That’s backwards. The label is the only objective data you have before buying, and reading it takes about 90 seconds once you know where to look.
The Four Things That Matter
1. Exact milligrams per serving. Every active ingredient should have a number next to it. Not “proprietary blend of glucosamine, chondroitin, and MSM totaling 15,000 mg.” That tells you nothing about how much of each ingredient you’re getting. A blend could be 14,500 mg of the cheapest filler ingredient and 500 mg of everything else. The label lets the manufacturer claim all three ingredients while hiding the fact that two are underdosed. Products that list individual milligrams for every active are telling you they have nothing to hide.
2. Chemical form. “Glucosamine” is not enough information. Glucosamine HCl delivers 28% more active compound per gram than glucosamine sulfate. “Zinc” could be zinc methionine (well-absorbed chelated form) or zinc oxide (poorly absorbed, cheap). The form name tells you which one is in the container. If the label just says the generic compound name without specifying the form, assume the manufacturer used the cheapest version available.
3. Serving size in grams. You need this number to calculate cost per day and to verify that the ingredient amounts add up. If a product claims 10,000 mg of glucosamine, 5,000 mg of MSM, and 2,000 mg of chondroitin per serving, that’s 17,000 mg (17 g) of active ingredients alone. If the serving size is listed as 10 g, something doesn’t add up. The math should work. When it doesn’t, the label is unreliable.
4. Weight-based dosing. A 350 kg Arabian and a 700 kg draft cross don’t need the same amount of anything. Good products provide dosing instructions that scale by body weight. Products with a single “one scoop per day” instruction regardless of horse size are either overdosing small horses or underdosing large ones.
Red Flags That Should Make You Suspicious
Proprietary blends. Any label that groups multiple active ingredients under a single total weight is obscuring individual amounts. There is no legitimate manufacturing reason to do this. Companies claim it protects their “unique formula.” It doesn’t. A competitor can reverse-engineer any supplement with basic lab analysis. The blend protects the company from customers discovering that the star ingredient on the front of the bag is present at a fraction of the therapeutic dose.
Ingredient lists with no amounts at all. Some supplements list ingredients with checkmarks or bullet points instead of milligrams. “Contains: glucosamine ✓, MSM ✓, chondroitin ✓, hyaluronic acid ✓.” That’s a marketing document, not a supplement label. You cannot evaluate dose, calculate cost efficiency, or compare products without numbers.
Vague quality claims. “Veterinarian recommended” means one vet said yes at some point. “Premium quality ingredients” is legally meaningless. “Made in the USA” tells you where the final mixing happened, not where the raw materials came from. The claims that actually matter are specific and verifiable: NSF Certified for Sport, a named cGMP facility, a Certificate of Analysis available on the website. Everything else is filler.
Good Labels vs Bad Labels
A strong label looks like Cosequin ASU’s: every active ingredient quantified in milligrams, trademarked specification names (FCHG49, TRH122, NMX1000) that correspond to published quality standards, clear serving size, weight-based dosing chart. You can look up those spec names and verify what they guarantee. That’s transparency.
A weak label gives you a long ingredient list, impressive-sounding botanical names, total blend weights, and no way to determine whether the product delivers a therapeutic dose of anything specific. We see this pattern often enough in our audit database that it’s predictable: products with poor label transparency almost always score poorly on dosing adequacy too. The companies that hide their amounts are usually the ones with amounts worth hiding.
How We Score This
Label transparency is one of six dimensions in our scoring system, worth up to 15 points. We break it into four sub-scores: active ingredient quantification, source/origin disclosure, serving and inactive ingredient details, and whether the product uses named specification standards. The math is public in every audit report’s source archive PDF.
Across the 10 joint supplements we’ve audited, label transparency scores range from 10 to 13 out of 15. The spread is narrower than you might expect, because most established equine supplement brands have learned that buyers check milligrams. Where the real separation happens is in source disclosure and specification standards. Only one product in our database scores full marks on specification standards. Most get 1 out of 2.
Frequently Asked Questions
Are supplement labels regulated for horses?
Equine supplements fall under AAFCO and state feed control regulations, not the FDA drug approval process. Labels must list ingredients and guaranteed analysis, but enforcement is inconsistent. There’s no pre-market approval. A company can put a product on shelves without proving its claims, which is why independent evaluation matters.
What if the label looks good but the product doesn’t seem to work?
Three possibilities. First, the dose may still be below the therapeutic threshold for your horse’s specific weight. Second, the condition may not be supplement-responsive (advanced arthritis, for example, won’t reverse with oral supplementation). Third, the label may be inaccurate, which is why third-party testing and Certificates of Analysis matter. A good label is necessary but not sufficient.
Should I trust “vet-recommended” claims on labels?
Not as a standalone decision factor. “Veterinarian recommended” has no regulated definition in equine supplements. It could mean the company’s staff vet approved the formula, or that they surveyed 100 vets and one said yes. Ask your own vet about specific products by name and dose, and bring the label so they can evaluate the actual formulation.