It can take several weeks and multiple treatments before you start experiencing relief from your migraines. Patients may take 4 weeks after injection to notice benefit, although many see improvement sooner. There is good evidence that when it works, Botox has a cumulative effect, with better and better response with each cycle administered every 4-6 months across a year. Therefore, patience is a virtue and trying Botox for 2–3 cycles may yield benefit not seen with just one set of injections. However, after 2–3 sets of injections, if no improvement is noticed, Botox should probably be discontinued. For those who do respond, injections are continued every 4-6 months.
Some patients find they can discontinue injections without frequent migraines returning. Others need regular treatments to keep migraines under control. To test whether it can be discontinued, the injections are spaced further apart and if the headaches do not increase, the Botox may be stopped.