Highest dosage-form of magnesium that is closest to getting a shot?

Hi everyone,
I get a magnesium shot once a week from my doctor. On those days I feel much improved, but the improvement only lasts a day. If I could get that high dose of magnesium daily I believe it would improve my health immensely. However, when I take oral magnesium at high doses (glycinate form) I tolerate it fine but I do not feel any effects like the I do with the shots. The same is true for transdermal magnesium. Is there any really concentrated form of magnesium I can take? I wish I could give myself magnesium shots daily. I wonder why doctors don't do this like they do with B12. Any suggestions would be greatly appreciated. Thanks

 

IV forms are chloride and sulphate. Perhaps epsom salt baths?