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Vet Insight: Adequan vs. Polyglycan for Equine Arthritis in 2025 🐴💉🦴
By Dr Duncan Houston, BVSc
Arthritis is one of the most common performance-limiting conditions in horses. Horse owners have a variety of treatment options, but not all are created—or regulated—equally. Among injectable joint therapies, Adequan and Legend remain the gold standards. Yet many owners ask if less expensive products like Polyglycan can do the same job. 💉🐎
In this 2025 arthritis treatment guide, Dr Duncan Houston clears the confusion around these joint injections and explains why FDA approval matters for both safety and effectiveness. 🧠⚖️
1. What Is Adequan? 💉
Adequan (polysulfated glycosaminoglycan or PSGAG) is an FDA-approved injectable drug specifically indicated for the treatment of arthritis in horses. It:
- 🛡️ Reduces inflammation inside the joint
- 💪 Protects cartilage from further damage
- 🧬 Stimulates cartilage repair
Adequan is backed by clinical research, has documented safety, and is one of the few equine joint products that meets stringent FDA standards. ✅
2. What Is Polyglycan? 🤔
Polyglycan is a sterile solution originally designed for joint lavage (flushing) after surgery. It contains hyaluronic acid, chondroitin sulfate, and glucosamine. However:
- 🚫 It is not FDA-approved for injection as a joint treatment
- 📄 There are no published studies showing its safety or efficacy for treating arthritis
Despite being labeled “for veterinary use,” Polyglycan is not a generic equivalent to Adequan or Legend. Calling it a “combo generic” is inaccurate and misleading. ❌
3. The Comparative Study: Adequan vs. Polyglycan 📊
A study conducted by the makers of Adequan involved 16 horses with chemically-induced joint inflammation. The results were clear:
| Outcome | Adequan | Polyglycan |
|---|---|---|
| Improvement in lameness | 88% | 50% |
| Reduction in joint swelling | 48% | 0% |
This suggests Adequan is consistently more effective at reducing both pain and inflammation. 💪📉
4. The Myth of “Generic Adequan” 🚫
A true generic drug is:
- ✅ Approved by the FDA for the same indication
- 🔬 Has the same active ingredients and safety profile
- 📦 Manufactured under identical quality standards
Polyglycan does not meet these criteria. It’s not a generic version of Adequan or Legend—it’s a different compound used off-label in horses. ⚠️
5. Safety Concerns with Unapproved Use ⚠️
Injecting a product not designed for that route or use may result in:
- 🔥 Joint irritation or infection
- 🦴 No improvement—or worsening—of arthritis
- 💔 False confidence leading to missed diagnoses
Always follow your veterinarian’s guidance when choosing joint therapies. 🧠
6. Cost vs. Efficacy: The Long-Term View 💰📈
While Adequan and Legend cost more upfront, their:
- 💉 Doses are proven and effective
- 🧪 Results are backed by research
- 💵 Can reduce long-term treatment costs by minimizing joint damage
Cheaper alternatives may offer short-term savings, but they may cost more in ineffective treatments or complications. 🧾
7. Summary Table: Adequan vs. Polyglycan 📋🧪
| Factor | Adequan | Polyglycan |
|---|---|---|
| FDA-approved for arthritis? | ✅ Yes | ❌ No |
| Backed by clinical studies? | ✅ Yes | ❌ No |
| Labeled for injection? | ✅ Yes | ❌ Originally for lavage |
| Reported improvement in swelling? | ✅ Yes (48%) | ❌ No (0%) |
| Used off-label? | ❌ No | ✅ Yes |
8. Final Thoughts from Dr Duncan Houston 💬
When it comes to managing arthritis in horses, effectiveness and safety matter more than cost. Adequan and Legend are proven tools, while Polyglycan remains unapproved and unproven for joint therapy. Stick with treatments backed by science—not just price. 🧠🐴
Need help creating a safe joint care plan for your horse? Visit AskAVet.com or download the Ask A Vet app 📲 for evidence-based treatment advice and product comparisons tailored to your horse’s condition.
— Dr Duncan Houston, BVSc
