Facial fillers are designed to smooth wrinkles, sculpt lips and shape facial contours. It is a clear, synthetic gel made with hyaluronic acid, a natural substance that is found throughout your body. It carries little risk of allergic reaction. The most common areas for treatment are the glabellar lines (between the eyebrows) and the nasolabial folds (from the root of the nose to the angle of your mouth and the lips). The results can last from six months to a year.