So having done loads of research of what is the best form of magnesium, I found some very good magnesium glycinate. It was recommended to me for my sleep by the doctor.
I used to get menstrual migraines and I can feel an underlying headache when I take these though I have to admit they have helped my sleep.
Looking up the side effect they are actually meant to make headaches better not worse but wondered if anyone else had experienced this before I give them up!