Interleukin 1-Receptor Antagonist Protein (IRAP)


IRAP is the newer technology available for treating arthritis, synovitis, and cartilage damage within joints. This anti-inflammatory protein is harvested from the horse’s own blood and works by stopping the production of Interleukin 1 within the joint.

Interleukin 1 is a protein produced by the joint that causes inflammation, which in turn leads to joint damage. IRAP binds to the site of Interleukin 1 production within the joint, effectively preventing release of this damaging protein.


IRAP is harvested by first drawing a blood sample into a syringe containing glass beads coated with chromium. Chromium stimulates the production of IRAP during a 24 hour incubation period at 37 C. After the sample has incubated for 24 hours, the sample is centrifuged and the IRAP is collected. Up to 4 doses can be obtained from a single syringe and the extra doses are frozen and stored for later use.

IRAP is much less irritating to the joint’s cartilage than steroids and helps prolong joint health. It is injected into the joint every 3 weeks for a total of 3-4 doses in lieu of steroid & hyaluronic acid injections. The series of IRAP injections can be repeated at any time.