Xanthurenic and Kynurenic Acids

Organic Acids

Code: 4470 (24-hour) / 4970 (dried urine)

Xanthurenic & Kynurenic Acids — Dried & 24-hour urine

Urine Organic Acids (DU & 24-Hour)
Code: varies by kit

Xanthurenic & Kynurenic Acids (Urine)

Targeted readouts from the kynurenine pathway to help contextualize inflammation,
B6 status, and metabolic stress. Available as dried urine (single-day)
or 24-hour liquid urine, with clinician-ready reporting.

Dried urine or 24-hour urine
Actionable organic acids
Quantitative report
Clinician-ready

Sample

Dried urine / 24-hour urine

Analytes

Xanthurenic, Kynurenic

Report

Quantitative values w/ refs

CPT

83921 × 2

View CPT Codes

83921 × 2

Order / Inquire
Sample Report — Dried Urine (PDF)
Sample Report — 24-Hour Urine (PDF)
Collection — Dried Urine (PDF)
Collection — 24-Hour Urine (PDF)

CLIA-certified laboratory

What this measures

Xanthurenic Acid (urine)
Kynurenic Acid (urine)
Reported quantitatively with reference intervals (format report-dependent)
May be accompanied by urine volume/creatinine context (24-hr variant)

Why these markers matter

Key products of the kynurenine pathway (tryptophan metabolism) that intersect
with immune tone, neurotransmitter balance, and hormone metabolism.

Context for B6 sufficiency and inflammatory stress
Adds nuance when evaluating metabolic or neuro-immune symptoms

Clinical context

Nonspecific complaints (fatigue, brain fog, low resilience)
Questions around estrogen metabolism or immune overactivation
Tracking B6 within nutrition, detox, or hormone protocols

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