Since you ask...
I currently take my magnesium in powdered citrate form. I take anywhere from 600mg - 900mg supplemental per day. I also take pretty hefty doses of oral Vitamin C. The only reason I point that out is that, for some individuals, that could be a recipe for disaster necessitating a bathroom in quite hurry. Believe it or not, this combo does not play havoc with my GI system (and I'm sans large intestine). Should you delve into the magnesium, start slow and gradually build the dose. I always, seemingly no matter what I'm putting into my body, increase the dose at a arbitrary three days unless a doctor is instructing me to do otherwise.
I've been on the citrate, but my new doctor is switching me over to a potassium - magnesium aspartate supplement. I didn't ask why, but will find out one of these days.
Citrate is a good, absorbable form. Other desirable forms are aspartate, malate, glycinate, and orotate. There may be others but those are the ones that I recall.
Whatever you do, especially if you find yourself with GI issues, start slow and build the dosage gradually.
Like others mention, heat is a winner for me too.
