Nothing about Botox is indefinite. It will wear off at some point. The brow is made up if depressor musces and elevator muscles. The depressor muscles are between the eyes, the area that produces the typical "11's", as well as in the crows feet region. The elevators are the frontalis muscle, which produces horizontal lines in the forehead. To soften these lines, they muscle is weakened with Botox. The side effect of this that if the depressor muscles are still full strength, the brow may be pulled down. In younger patients, this might not be an issue, but otherwise this can lead to drooping of the brow. The upper forehead becomes a "yin and yang" of form and function. I very rarely inject the frontalis without injecting the depressor muscles to help counteract some of the potential droopiness or heaviness potential. You may want to discuss this with your injector after a few weeks. We usually give the Botox at least that long to settle.