Has anyone had any luck with taking magnesium supplements?  If so, how many mg per day?  I had read that there was some luck with injecting it, but doubt that is and option for me, so I thought about trying the tablets.  Looking for anything that helps at this point... going into my third month now... and covered/stocked meds have dwindled.

The original studies found about 40% of people with cluster headaches saw clinical improvement from magnesium.  They used intravenous magnesium, which is probably going to be quicker and more noticeable than tablets.  They also found that people who had the lowest magnesium levels were more likely to respond.

From what I've seen of the research, magnesium deficiencies are pretty common.  I think a moderate magnesium supplement makes sense for many people with clusters.  There is a long list of conditions associated with low magnesium - including metabolic syndrome, low HDL, high blood pressure, many types of arrhythmia, chronic inflammation, etc etc.

I agree that magnesium is not a good monotherapy - alone, it likely won't be enough.  But if part of the problem is a magnesium deficiency, it should be considered essential.