Be careful!
Concerning the tests on metabolic nutrition's creatine glycerol phosphate, you must think twice about the results.
They claim 10g of creatine-glycerol-phosphate, which is a big molecule, which once dissolved will be equivalent to about 6g of creatine monohydrate, which is exactly what the results show. They did NOT claim 10g of creatine monohydrate, they claimed 10g of creatine-glycerol-phosphate. Further, I'm not even sure if testing for glycerol & phosphate separately would even work on this product, since the compound molecule may not show up at all, so it doesn't surprise me if there was no glycerol or no phosphate.
Likewise, if a product claims 10g of creatine citrate, it does not have 10g of creatine monohydrate in it. It has 10g of creatine citrate, which once dissolved will be equivalent to about 4-5g of creatine monohydrate.
Eric
BC, Canada