Some of the adverse effects of SYNVISC may include:’ Chills, Difficulty breathing, Dizziness, Fever, Fluid build-up around the knee, Headache, Heat, hives, Itching, Muscle pain, Pain, Rash, Redness, Swelling, Thrombocytopenia Speak with your doctor for a full list of side effects. SYNVISC can only be administered by a healthcare professional, so before purchase, ensure that your doctor or another healthcare provider can safely administer the medication to you. SYNVISC requires a prescription from a licensed healthcare professional.