Flex+Max. It delivers 2,800 mg more glucosamine per serving, costs two cents more per day, and covers more ground with omega-3s and full-dose HA.
Cosequin ASU is the most verifiable product in our database. Trademarked ingredient specs, a documented QC program, and the only QA score above 5 in ten audits. If you want to know exactly what’s in the scoop, nothing else comes close. But Flex+Max puts 10,000 mg of glucosamine in your horse — Cosequin puts 7,200. That gap decides this.
The Scores
| Flex+Max | Cosequin ASU | |
|---|---|---|
| Overall | 6.9 | 6.5 |
| Label Transparency | 12 / 15 | 12 / 15 |
| Ingredient Form | 15 / 20 | 15 / 20 |
| Dosing Adequacy | 15 / 20 | 12 / 20 |
| Formula Design | 13 / 15 | 10 / 15 |
| Quality Assurance | 2 / 15 | 6 / 15 |
| Value | 12 / 15 | 10 / 15 |
| Badge | Recommended | Recommended |
| Cost/day | $1.75 | $1.73 |
2,800 mg of Glucosamine Per Scoop. That’s the Whole Story.
Flex+Max delivers 10,000 mg of glucosamine HCl per serving. Full therapeutic threshold. Cosequin ASU delivers 7,200 mg. That’s 72% — enough to score 5/8 on the primary active, but a meaningful shortfall for a horse in regular work.
The 2,800 mg gap matters because glucosamine is the single most important ingredient in a joint supplement. It’s the substrate your horse’s body uses to build cartilage and glycosaminoglycans. Every other ingredient in these formulas plays a supporting role. When the foundation is short, the supporting cast can’t make up the difference.
Cosequin partially compensates with ASU — avocado/soybean unsaponifiables at 1,050 mg, which exceeds the 1,000 mg research threshold. ASU works through a different pathway, reducing inflammatory mediators rather than building cartilage directly. It’s a useful ingredient backed by equine research that Flex+Max doesn’t have. But it doesn’t replace the missing glucosamine. It complements it, and there’s less of it to complement.
Flex+Max also delivers 150 mg of hyaluronic acid (threshold: 100 mg) where Cosequin has none. HA supports synovial fluid viscosity — the lubricant inside the joint. Between the glucosamine gap and the HA, Flex+Max scores 15/20 on Dosing Adequacy versus Cosequin’s 12/20.
Cosequin’s QA Score Is the Best We’ve Seen. It’s Not Enough.
Cosequin ASU scores 6/15 on Quality Assurance. That doesn’t sound impressive until you see that every other product in our database scores 1 or 2. Nutramax uses trademarked ingredient specifications — FCHG49 for glucosamine, TRH122 for chondroitin, NMX1000 for MSM — which means published purity and potency standards exist for each batch. The company describes 80+ quality checks in their manufacturing process and explicitly claims contaminant testing.
Flex+Max scores 2/15. Absorbine states “Made in the USA” and not much else. No trademarked specs, no public COA, no named third-party certifier. That doesn’t mean the product is bad. It means we can’t verify the label claims independently, and the scoring system cares about what’s provable.
For competition horses subject to drug testing, this matters. Nutramax’s documented QC program gives you more confidence that what’s on the label is what’s in the scoop, with no undisclosed substances. If your horse competes under FEI or USEF rules and a positive test ends your season, Cosequin’s paper trail has real value that our scoring system undersells at 4 points apart.
What’s in Each Scoop
| Ingredient | Flex+Max (75 g) | Cosequin ASU (17.5 g) | Threshold |
|---|---|---|---|
| Glucosamine HCl | 10,000 mg | 7,200 mg | 10,000 mg |
| MSM | 5,000 mg | 5,000 mg | 10,000 mg |
| Chondroitin sulfate | 1,200 mg | 1,200 mg | 2,500 mg |
| Hyaluronic acid | 150 mg | — | 100 mg |
| ASU | — | 1,050 mg | 1,000 mg |
| Boswellia | 130 mg | present | 300 mg |
| Flaxseed | 11,000 mg | — | — |
| Rice bran | 5,600 mg | — | — |
| Manganese | — | present | 50 mg |
| Cost/day | $1.75 | $1.73 |
Which One for Your Horse
If your horse competes at rated shows and you lose sleep over contamination risk, buy Cosequin ASU. The trademarked specs and documented QC program are worth paying for when a positive drug test costs you a season. The glucosamine is underdosed, but the ASU compensates through a different joint-support pathway, and you know exactly what you’re feeding.
If your horse is a trail horse, a lesson horse, a retiree with creaky hocks, or anything that doesn’t face a drug test, Flex+Max is the better product. More glucosamine, full-dose HA, omega-3 sources, and two cents more per day. The only thing you’re giving up is the ability to verify the label to pharmaceutical standards. For most horse owners, that trade is easy.
Flex+Max is our #1 joint supplement. Cosequin ASU is #3. Both earn the Recommended badge. But the gap between them is wider than the score table suggests, because 2,800 mg of glucosamine every single day adds up to a lot of cartilage your horse either builds or doesn’t.
Frequently Asked Questions
My vet recommended Cosequin. Should I ignore that and buy Flex+Max?
No. Your vet knows your horse. Cosequin ASU is a well-researched product backed by Nutramax’s clinical studies and trademarked ingredient specs. If your vet chose it for a specific reason — competition safety, a known condition, compatibility with other medications — follow that advice. Our audit measures what’s on the label and at what dose. Your vet measures your horse.
Is ASU better than hyaluronic acid?
They do different things. ASU reduces inflammatory mediators that break down cartilage. HA supports the viscosity of synovial fluid that lubricates the joint. Neither replaces the other. In an ideal world you’d have both, but no product in our database delivers full-dose ASU and full-dose HA in one scoop. If forced to pick one, ASU has stronger equine research behind it. But Flex+Max’s HA at 150% of threshold is nothing to dismiss.
Full audit reports: Flex+Max Pellets | Cosequin ASU Pellets