I have had cluster headaches for 40 years. I use Verapamil only when I am in a cycle and it is a huge help to reduce the frequency and intensity of headaches, and makes them easy to stop with oxygen, in 1-2 minutes. Once the cycle stops, I taper off the verapamil and then typically have 18 months between cycles. The downside is that I only started using verapamil 5 years ago, and since then my cycles have quickly gotten longer, now up to 5 months. So I am suspicious that it makes cycles longer, but my cycles have been slowly getting longer anyway as I age, so cannot say for sure.
