I've found two US labs that perform a KPU test to diagnose pyr(r)oluria: https://pyroluriatesting.com/ http://store.riordanclinic.org/product/LPyr.html Does anyone have experience with either lab? Does anyone have a recommendation? I am confused by the plethora of names for the substance(s) they are testing, especially because I keep running across the disclaimer that the "krypto" part is a misnomer. The first lab gives a chemical name of: "Hydroxyhemopyrrolin-2-one (HPL)" The second lab: "The chemical structure is a 2,4 dimethyl-3-ethylpyrrole." Can anyone tell me whether they are testing the same substance? Thanks!