"The pain doesn't go away permanently, however. After several months, the nerves sprout new pain fibers, and the headaches tend to return. The Botox effect usually lasts about two-and-a-half months." Mar 19, 2016 Mayo Clinic

Here's an interesting article: https://americanmigrainefoundation.org/resource...

Has anyone else been using it long-term and finding it helpful? It is apparently effective in the 12-week range.