I tried these for several years as they were the favored, well, really the only treatment offered by my neurologist at the time. They did nothing for me, and triggered a migraine every time. We eventually switched neurologists, and now I get botox, which works very well. I've talked to many people for whom nerve blocks work, so I think it may just depend on the triggers for your migraines (the same way migraine surgery will work for some and not others.)