Citrulline

ChemistryAlso known as: L-CitrullineAlso known as: 2-Amino-5-ureido-pentanoic acidnmol/mL

The concentration of the amino acid citrulline in your urine.

Normal Range
15 – 45 nmol/mL
nmol/mL
Abnormal Levels
Consult your provider
Specimen Type
Blood

Why This Biomarker Matters

Abnormal citrulline levels can signal rare genetic metabolic disorders or kidney problems that require specialized diagnosis and management.

Understanding Your Results

Normal Range

15 – 45 nmol/mL

Overview

Citrulline is an amino acid involved in the urea cycle, which processes nitrogen waste in your body. Urine citrulline levels reflect your body's amino acid metabolism and kidney filtration. Abnormal citrulline levels can indicate genetic metabolic disorders affecting amino acid processing, kidney disease, or nutritional deficiencies. This test is most commonly ordered when metabolic disorders are suspected or during investigation of unexplained symptoms like developmental delays, seizures, or organ dysfunction.

Technical Information (LOINC Codes)

Standardized laboratory codes for this biomarker

20640-9Primary
Citrulline [Moles/volume] in Serum or Plasma
umol/L
27056-1
Citrulline [Moles/volume] in Urine
nmol/mL
2129-5
Citrulline [Presence] in Serum or Plasma
42892-0
Citrulline [Moles/volume] in DBS
umol/L
25376-5
Citrulline [Moles/time] in 24 hour Urine
umol/(24.h)
22722-3
Citrulline [Moles/volume] in Specimen
umol/L
22654-8
Citrulline [Moles/volume] in Cerebral spinal fluid
umol/L
49629-9
Citrulline [Presence] in Urine
25877-2
Citrulline [Moles/volume] in 24 hour Urine
nmol/mL
26745-0
Citrulline [Moles/volume] in Amniotic fluid
umol/dL
32234-7
Citrulline [Moles/volume] in Vitreous fluid
umol/L
32235-4
Citrulline [Moles/volume] in Body fluid
umol/L

Available Lab Tests

Order tests that measure this biomarker

Amino Acids (Plasma)

$193.00
Results in 3-7 business days