Urinary Test for Pyroluria

Manneken PisPyroluria is caused by an inborn error in synthesizing and metabolizing hemoglobin resulting in elevated levels of hydroxyhemopyrrolin-2-one (HPL) as well as kryptopyrrole (KPU, 2,4 dimethyl-3-ethyl pyrrole), which are excreted in the urine.

As these pyrroles bind to – and thus deplete – zinc, vitamin B6, and omega 6, pyroluria is associated with deficiencies of these nutrients as well as a deficiency of serotonin, a neurotransmitter whose synthesis requires vitamin B6. Elevated levels of pyrroles also cause a variety of behavioral, neurological, and cognitive symptoms, including irritability, poor stress control, mood swings, impaired short term memory, and depression. Higher concentrations of pyrroles have been found in the urine of patients with autism, learning disabilities, alcoholism, ADHD, depression, bipolar disorders, Down Syndrome, schizophrenia, and possibly chronic Lyme disease. Both KPU and HPL are known to be associated with abdominal pain, acute intermittent porphyria (AIP), and/or haemolytic crisis.

The urinary KPU test can confirm pyroluria and thereby facilitate appropriate diagnosis and treatment, generally involving supplementation with zinc and vitamin B6.

Interpretation of KPU results

< 15   µg/dL: negative (no evidence of pyroluria)
15 - 25   µg/dL: elevated (may benefit from treatment)
> 25   µg/dL: positive (treatment recommended)
> 50   µg/dL: strongly positive (treatment strongly recommended)


  1. McGinnis W, Audhya T, Walsh W et al. Discerning the Mauve factor, Part I. Alternative Therapies in Health and Medicine, 14:40-50, 2008.
  2. McGinnis W, Audhya T, Walsh W et al. Discerning the Mauve factor, Part II. Alternative Therapies in Health and Medicine, 14:56-62, 2008.