Silicea cold sore lip gel is a natural acting formulation used to treat cold sores the active ingredient is silica gel silicic acid gel a compound formed from silica and water the gel binds cold sore secretions to the gel drying out blisters helping the symptoms of cold sores and inhibiting the spread of the virus kosher certified silicea cold sore lip gel is a natural acting formulation used to treat cold sores the active ingredient is silica gel silicic acid gel a compound formed f