What are the side effects of synvisc (hylan g-f 20)?

Synvisc (hylan g-f 20): Synvisc (hylan g-f 20) is an animal product, made out of the rooster's comb (red object on the rooster's head). One of the side effects is allergic reaction, especially if one is allergic to chicken products (eggs, etc). This is fairy uncommon, but it can result in a painful, swollen joint. Other potential side effects are infection from the injection itself and local skin/soft tissue reaction.