There are a few websites that sell a product called ionic magnesium. They say the ionic bonds are already broken in the chemical, therefore no digestion must occur for the magnesium to enter the cells, allowing for 100% bioavailability.
I ordered a product called Ionic Fizz, and another product called Trace Minerals Ionic Magnesium is coming. I received the Ionic Fizz today, and have taken 1200 mg, according to the label. No diarrhea yet, as would come about with only 800 mg of magnesium glycinate tablets. Soon after each dose I think I felt more tired, and possibly less anxious. I'll let you guys know how the rest of the trial goes.
Oh, and I stopped taking Zoloft a few weeks ago. At first I had some brain zaps, but they went away for the most part. They seem to have reappeared a little bit today, which could be caused by any of the number of ingredients in Ionic Fizz.