Frequently Asked Questions

Noltrex^®Vet is a synthetic joint lubricant with physical properties similar to healthy synovial fluid.  Noltrex^®Vet mitigates a root cause of sore joints by mechanically reducing friction, improving boundary lubrication, and providing physical protection to articular cartilage. Unlike other viscosupplements, Noltrex^®Vet aggregates to damaged articular cartilage surfaces¹, producing a fine and lubricating film.

Noltrex^®Vet and hyaluronic acid both work to reduce friction in the joint.  However, Noltrex^®Vet has a much longer residence time within the joint, thus providing the benefit of reduced friction for much longer.  In addition, Noltrex^®Vet has been found to aggregate on both damaged and healthy cartilage, thus providing lubrication where it counts, on the cartilage surface.

Noltrex®Vet and Arthramid Vet® are the most common polyacrylamide gels used in equine joints. Differences between polyacrylamide gels are not evident by typical means of comparison, such as concentration, but are determined by their manufacturing process and molecular structure. It is these differences that alter the ultimate function of the gel. Arthramid Vet® acts primarily on the synovial membrane, while Noltrex®Vet provides lubrication and physical protection to the cartilage surface. As these products vary in their mechanisms of action and how they function within the joint, each horse should be evaluated individually to determine the most appropriate course of treatment.

Other intra-articular injections (steroids or Orthobiologics) address inflammation at some level.  Only Noltrex^®Vet provides an important lubricating layer at the cartilage surface.  Noltrex^®Vet is therefore an excellent complement to these other therapies in long-term joint health management.

The short answer is any joint. Initially, Noltrex^®Vet was recommended for high motion joints. Common examples would include coffin joints, fetlocks and stifles. However, other joints considered low motion joints (limited movement, but important) have also shown great improvement from Noltrex^®Vet therapy. The most common example of a low motion joint would be lower hock joints.

Response to treatment with Noltrex^®Vet will vary between horses. Some horses show improvement within days after injection, while others may take up to 30 days. Generally, gradual improvement is seen over a 1-3 week period. If a horse makes improvement from a single injection, but is not 100%, then a second injection after 5-6 weeks should be considered.

The short answer is yes. Remember to understand your whole horse, not just the joint condition. Horses with Cushing’s like syndrome, stomach ulcers (EGUS) or prior laminitis events are all sensitive to certain other products that could be used in joint treatment. Noltrex^®Vet is a safe, effective substitute in these horses.

Long-term joint management requires a strategy and often a combination of therapies.  Long duration therapy combinations lead to less joint injections and more reliable responses to therapy over time.

The most common combination therapy used in articular injections in horses today is triamcinolone and hyaluronic acid. Over time, horses tend to respond for shorter periods of time to this therapy. Clinical experience has indicated that switching to Noltrex^®Vet and Triamcinolone as the next step in the management of these cases often results in minimal downtime and can have resolution of lameness lasting between 6 to 24 months.

Equine practitioners have reported that by adding Noltrex^®Vet to an orthobiologic therapy horses often remain sound and in training while those therapies work in the background to improve the overall joint condition over time.

Over time, Noltrex^®Vet is broken down into smaller pieces due to normal friction within the joint. Once the particles are of small enough size, they are removed from the joint by a naturally occurring absorption and removal process at about 30-60 days post-injection. This function ensures no residual Noltrex^®Vet (polyacrylamide) particles remain in the joint once it is no longer of benefit. In comparison, hyaluronic acid concentration decreases within hours after injection.

There have been over one million injections of the human product Noltrex^®  worldwide.  And more than 60,000 doses of Noltrex^®Vet have been used in horses in North America. To date the number of adverse events reported are equal or less than adverse events from other conventional intra-articular therapies.

Noltrex^®Vet is sold only to licensed veterinarians the United States and Canada and must be purchased directly from Nucleus ProVets by licensed veterinary account holders. To order, simply log into your account or call 888-550-0071.

Absolutely! The only difference is it’s an extra-label use of the product, so it requires a conversation between the veterinarian and the owner. Many products veterinarians use are extra-label, so this is not an unusual practice.