while chlorophyll in plants contains plenty of magnesium, the liquid chlorophyll sold in health stores contains none, instead sodium and copper have been substituted for the magneusium. I dont really understand why, but apparently that substitution makes the liquid more stable. so, if the bottled chlorophyll is benefitting you, its not because its giving you magnesium, it may have something more to do with its blood building properties or its overall body detox affects.
look on any label of any bottle of chlorophyll sold and you will see 'sodium copper chlorophyllin' as the main ingredient. no magnesium is ever listed.
Edit -- btw, this makes me wonder about copper. perhaps you are copper deficient? thats something to look into, each serving of liquid chlorophyll has about 4 mg of copper. are you familiar with dr. larry wilson? he is the copper expert.