Proposed hyaluronic acid (HA) mechanism of action*
The precise mechanism of action of HA is unknown; however, proposed mechanisms of HA activity include:
ReplacesOA synovial fluid with higher HA concentration—improves viscosity10
Restoresshock-absorbing, lubricating ability of depleted synovial fluid11
Exogenous HA can catalyze physiological response†
The synthesis of hyaluronan within synovial joints may be influenced by the concentration and molecular weight of hyaluronan in the extracellular environment.
HYALGAN® is a viscous solution with a molecular weight (500,000-730,000 daltons) fraction of purified natural sodium hyaluronate in buffered physiological sodium chloride, having a pH of 6.8-7.5. The sodium hyaluronate is extracted from rooster combs. Hyaluronate (also known as hyaluronan or HA) is a natural complex sugar of the glycosaminoglycan family and is a long-chain polymer containing repeating disaccharide units of Na-glucuronate-N-acetylglucosamine.14
- Clinical significance in vivo has not been demonstrated.
- Within the molecular-weight range of US-approved HAs used in the treatment of OA knee pain, it is unknown what role these physiological processes may play in clinical benefit.