In this double-blinded (physician and patient) randomized controlled clinical trial, the patient's left and right brows are randomized to either the placebo or treatment arm of the study and maintain this designation for the entirety of the study. This randomization is performed and recorded by the study nurse in the physician's office. This study nurse also will be responsible for preparing the placebo 0.9% Normal Saline (0.9%NS) and the 50mg/mL 5-Fluorouracil (5-FU). Both placebo and 5-FU are placed into identical syringes with 30 gauge needles, both materials are identical in color and clarity, making it impossible for physician or patient to correctly identify which injection is which without a label. Only the study nurse will be aware of which injection is which, and the nurse will ensure that the correct injection is placed into the correct brow at each visit via the study log that the nurse maintains.