Adequan is the brand name for polysulfated glycosaminoglycan (PSGAG), an injectable medication that is the only FDA-approved disease-modifying osteoarthritis drug (DMOAD) for dogs. Unlike joint supplements that provide building blocks for cartilage, Adequan works within the joint itself to inhibit destructive enzymes, stimulate cartilage repair, and improve joint fluid quality. It is also FDA-approved for intramuscular and intra-articular use in horses. Adequan represents a true pharmaceutical treatment for osteoarthritis, distinct from over-the-counter supplements such as glucosamine and chondroitin.
What Is Adequan Used For?
Adequan is prescribed for the treatment of non-infectious degenerative and/or traumatic joint dysfunction and associated lameness. Specific uses include:
Dogs (Adequan Canine)
- Osteoarthritis (OA) — the primary indication. Adequan is FDA-approved for canine non-infectious degenerative and/or traumatic arthritis.
- Degenerative joint disease associated with hip dysplasia, elbow dysplasia, and cruciate ligament injury.
- Post-surgical joint support following procedures such as TPLO (tibial plateau leveling osteotomy), TTA, or joint replacement.
- Early intervention in dogs diagnosed with joint disease to slow cartilage degeneration.
Horses (Adequan Equine / Adequan i.m.)
- Non-infectious degenerative joint disease including osteoarthritis.
- Traumatic joint injuries.
- Post-surgical joint rehabilitation.
- Available as both intramuscular (IM) and intra-articular (IA) formulations for horses.
How Does Adequan Work?
Adequan’s mechanism of action differs fundamentally from oral joint supplements. PSGAG works through multiple pathways:
- Inhibits cartilage-degrading enzymes: PSGAG blocks the activity of enzymes (including metalloproteinases and serine proteinases) that break down cartilage in osteoarthritic joints.
- Stimulates cartilage repair: PSGAG promotes the synthesis of proteoglycans and collagen by chondrocytes (cartilage cells), supporting the structural integrity of joint cartilage.
- Improves synovial fluid quality: PSGAG enhances the production of hyaluronic acid in the joint fluid, improving lubrication and shock absorption.
- Reduces inflammation: PSGAG has anti-inflammatory effects within the joint capsule.
After intramuscular injection, PSGAG reaches therapeutic concentrations in the joint fluid within two hours. Studies using radiolabeled PSGAG have demonstrated that the drug concentrates in articular cartilage, synovial membrane, and synovial fluid, confirming that it reaches the target tissues.
Evidence
Adequan stands out in the veterinary joint health market because it is backed by controlled clinical trial evidence, not just in vitro studies or anecdotal reports.
Key Clinical Evidence (Dogs)
- Controlled clinical trials supporting FDA approval demonstrated significant improvement in range of motion and reduction in lameness scores in dogs with osteoarthritis.
- Two pivotal randomized controlled studies showed that PSGAG-treated dogs had significantly better outcomes compared to control groups, including improved joint function and reduced pain.
- Adequan is the only FDA-approved DMOAD for dogs, a designation that requires evidence of disease modification (slowing or reversing cartilage damage), not just symptom relief.
Key Clinical Evidence (Horses)
- Controlled studies in horses demonstrated improvements in joint function and reductions in lameness.
- Intra-articular Adequan has shown cartilage-protective effects in equine joint disease models.
How This Compares to Supplement Evidence
- Glucosamine/chondroitin (Cosequin, Dasuquin): Mixed evidence. Some positive studies but no RCT data strong enough for FDA approval as a drug. These are classified as supplements, not pharmaceuticals.
- Adequan: Strong RCT evidence supporting FDA drug approval as a DMOAD. This is the critical distinction — Adequan has met the regulatory burden of proof that supplements have not.
Dosage
Your veterinarian will determine the appropriate dose and injection schedule for your pet.
Dogs (Adequan Canine)
| Phase | Dose | Route | Frequency | Duration |
|---|---|---|---|---|
| Loading series | 2 mg/lb (4.4 mg/kg) | Intramuscular (IM) injection | Twice weekly | 4 weeks (8 injections total) |
| Maintenance | 2 mg/lb (4.4 mg/kg) | IM injection | As needed (typically monthly or as directed) | Ongoing |
- The standard protocol is 8 injections over 4 weeks (twice weekly), followed by periodic maintenance injections as determined by your veterinarian.
- Each vial contains 100 mg/mL in a 5 mL vial (500 mg total).
- Many veterinarians teach owners to administer the IM injections at home after the initial loading series, reducing the need for repeated veterinary visits.
Horses (Adequan Equine)
- IM formulation: 500 mg IM every 4 days for 7 treatments
- IA formulation: 250 mg per joint, intra-articularly, at weekly intervals for 5 weeks
- Maintenance protocols vary by veterinarian and horse’s response
How to Give Adequan
For Dogs (Owner-Administered IM Injection)
Many veterinarians will demonstrate the injection technique and allow owners to administer subsequent injections at home. Key points:
- Adequan is given as an intramuscular injection, typically into the large muscles of the thigh (quadriceps) or lumbar region.
- Use proper aseptic technique (clean the injection site, use a new needle for each injection).
- Alternate injection sites between sessions.
- Your veterinarian will provide specific instructions for your dog’s size and the appropriate needle gauge.
For Horses
- IM injections are given in the large muscles of the neck or hindquarters.
- IA (intra-articular) injections must be performed by a veterinarian under sterile conditions.
Side Effects
Adequan has a strong safety profile with few reported side effects.
| Common Side Effects | Rare/Serious Side Effects (Contact Your Vet) |
|---|---|
| Mild pain or swelling at injection site | Abnormal bleeding (if pre-existing coagulopathy) |
| Transient diarrhea (uncommon) | Signs of allergic reaction (swelling, hives, difficulty breathing) |
| Joint infection (extremely rare, primarily with IA injection in horses) |
Bleeding Precaution
PSGAG has mild anticoagulant properties (it is structurally related to heparin). While clinically significant bleeding is rare at standard doses, Adequan should not be used in animals with known bleeding disorders or those receiving anticoagulant therapy. Discuss any concerns with your veterinarian.
Drug Interactions
- Anticoagulant medications (heparin, warfarin): Potential additive effect on bleeding time. Use with caution and under veterinary supervision.
- NSAIDs: Adequan can be used concurrently with NSAIDs. Many treatment protocols combine Adequan with oral pain management.
- Other joint therapies: Adequan can be used alongside physical therapy, weight management, and joint supplements as part of a multimodal osteoarthritis management plan.
Contraindications
Adequan should not be used in:
- Animals with known bleeding disorders or coagulopathies
- Animals receiving anticoagulant therapy (without veterinary oversight)
- Animals with known hypersensitivity to PSGAG
- For intra-articular use in joints with active infection
Cost & Availability
Adequan is a prescription medication available only through veterinary clinics and licensed pharmacies.
Dogs
- Per injection: Approximately $50-80 per injection (varies by dog size and region)
- Loading series (8 injections): Approximately $400-640 total
- Maintenance: Varies based on injection frequency; typically $50-80 per monthly or as-needed injection
- No generic available: There is currently no generic PSGAG product FDA-approved for dogs
Horses
- Per injection: Approximately $40-70 per injection
- Treatment series (7 injections): Approximately $280-490 total
- Generic availability: Limited
Adequan vs. Joint Supplements
| Feature | Adequan | Dasuquin | Cosequin |
|---|---|---|---|
| Type | FDA-approved drug (DMOAD) | Supplement | Supplement |
| Administration | IM injection | Oral chew/tablet | Oral chew/tablet |
| Evidence level | Strong (RCTs, FDA approval) | Moderate | Moderate |
| Disease modification | FDA-approved for disease modification | Not proven | Not proven |
| Monthly cost | $50-80/injection (maintenance) | $40-70/month | $20-40/month |
| Prescription required | Yes | No (vet-recommended) | No |
| Convenience | Requires injections | Daily chew | Daily chew |
Many veterinarians use Adequan in combination with oral joint supplements as part of a comprehensive osteoarthritis management plan that also includes weight management, controlled exercise, physical therapy, and pain medications as needed.
Frequently Asked Questions
Is Adequan better than glucosamine supplements? Adequan has stronger clinical evidence and is the only FDA-approved DMOAD for dogs, meaning it has demonstrated disease-modifying effects in controlled trials. Oral joint supplements like Dasuquin and Cosequin have moderate evidence and may provide benefit, but they have not met the regulatory standard for disease modification. Your veterinarian can help determine whether Adequan, supplements, or both are appropriate for your dog.
Can I give the injections at home? Many veterinarians teach owners to administer Adequan IM injections at home after demonstrating proper technique. This makes the maintenance phase more convenient and less expensive (avoiding office visit fees). However, always follow your veterinarian’s guidance on injection technique and schedule.
How long does it take to see improvement? Some dogs show improvement during the loading series (within the first 2-4 weeks). Others may require the full course before noticeable clinical improvement. Response varies by individual, severity of disease, and other factors. Your veterinarian will assess your dog’s response.
Is Adequan a lifetime treatment? Many dogs benefit from periodic maintenance injections after the initial loading series. The frequency and duration of maintenance therapy is determined by your veterinarian based on your dog’s clinical response. Some dogs may eventually be managed with less frequent injections.