The Metametrix test was through a
nutritionist, the other ordered by a Homeopathic Doctor. They were mostly the same
test, with a few more metabolites added onto the Great Plains test. I'm glad we did the second one, or we wouldn't have found the oxalic acid problem. He had significant hyperoxaluria. (I believe it's an acquired problem for him, not the "inborn metabolic error" type).
Yes, these are tests you do at home and then mail directly to the lab.