Hoping you are getting closer to success, Siegfried. I have wondered why Indo, but not other anti-inflammatories, is the best treatment for hemicranias. Found this today, which partly resolves my curiosity about that: "Indomethacin is one of the cyclooxygenase 1 inhibitors with the highest penetration rate in the blood-brain barrier.1 Indomethacin, but not other NSAIDs (ie, naproxen and ibuprofen), was found to inhibit nitrous oxide-dependent vasodilation. Other medications that could be considered for HC include topiramate, lamotrigine, naproxen, lithium, onabotulinumtoxinA, and melatonin." It's from a good recent article with good additional references: https://www.clinicalpainadvisor.com/home/topics/migraine-headache/hemicrania-continua-diagnosis-and-treatment/ (Melatonin is frequently mentioned in the literature as having a structure very similar to Indomethacin.)