Pyroluria: Fact or Fiction?

Objective: The term Mauve factor (pyrroluria) dates back to 1958 when Dr. Abram Hoffer defined the condition as elevated levels of pyrroles in urine, currently called hydroxyhemepyrrolin-2-one (HPL). It was suggested that raised pyrrole lead depletions zinc and vitamin B6, which, turn, were hypothesized result a range psychiatric disorders, such schizophrenia, anxiety, depression. Treatment implications are supplementation with B6. This article aimed review scientific literature associating pyrroluria symptoms, explore validity HPL testing, role nutrients treatment options for pyrroluria, discuss future research directions. Methods: A PRISMA conducted using search results from electronic databases PubMed, MEDLINE, PsycINFO, EMBASE inception February 2020 following keywords: hydroxyhemepyryrrolin (HPL), kryptopyrrole (KP), mauve factor, pyroluria, monopyrroles. Article reference lists also scanned included where relevant. Results: Seventy-three articles identified which only three studies significantly higher population compared controls, there no placebo-controlled trials directed at pyrroluria. other 13 clinical either showed association or did not provide adequate data show group differences levels. Despite an extensive history practitioners diagnosing treating wide variety mental health conditions associated well observations being clear following: (1) is robustly increased (2) urine excretion (3) high-dose B6 efficacious problems HPL. Conclusions: Elevated clinically observed, but poorly researched biomarker unclear associations disorders. Based on current evidence, testing recommended screening tool. Further required areas: establishment specific populations exhibit HPL, validation chemistry controlled establish efficacy pyrroles.