Has anyone used hyaluronic acid, for treating arthritis?

Minimally effective!: Some benefit if injected into joints in various forms by a doctor. They do require a series of 3-4 injections per joint, and some benefit, additive with nsaids, showed better relief of pain. However, and this is big: no clinical studies show delayed progression of osteoarthritis, as of yet! losing weight is more effective, certainly for weight bearing joints!

Yes: I use it freqently for persons with moderate knee arthritis. It is safe well tolerated and works pretty well for about a six month period of time. It does not cure anything but i find it works for a few years in an individual. At that point the arthritis has worsened and then knee replacement is usually necessary.