Last update Jan. 22, 2022

Carbon-13 labelled Urea


Safe substance and/or breastfeeding is the best option.

Carbon 13 (13C) is a natural, stable and non-radioactive isotope (Idifarm 2016, Osaka 2016) that is used to label urea for diagnostic purposes.

Since the last update we have not found any published data on its excretion in breast milk.

Urea is a natural component of the body and is also found in milk. (Wheeler RA 1991, Ross SA 1985)

The dose of urea from the breath test to rule out infection by Helicobacter pylori is 100 mg, an inconsequential amount since the endogenous production of urea is 25-35 g daily. (AEMPS 2004)

Manufacturer's data indicate low risk for pregnancy and breastfeeding. (Idifarm 2016, Isomed 2004)

Breast-feeding is protective against Helicobacter pylori infection. (Chak 2009)

See below the information of these related products:

  • Carbon-14 labelled Urea (Safe substance and/or breastfeeding is the best option.)
  • Urea (Safe substance and/or breastfeeding is the best option.)


We do not have alternatives for Carbon-13 labelled Urea since it is relatively safe.

Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Carbon-13 labelled Urea is also known as

Carbon-13 labelled Urea in other languages or writings:


Carbon-13 labelled Urea belongs to this group or family:


Main tradenames from several countries containing Carbon-13 labelled Urea in its composition:


Variable Value Unit
Oral Bioavail. 100 %
Molecular weight 76 daltons
Tmax 2 hours
3 hours


  1. Idifarma. Urea C13 Drug Summary. 2016 Full text (in our servers)
  2. Otsuka. Urea C13. Dril Summary. 2016 Full text (in our servers)
  3. Chak E, Rutherford GW, Steinmaus C. The role of breast-feeding in the prevention of Helicobacter pylori infection: a systematic review. Clin Infect Dis. 2009 Feb 15;48(4):430-7. Abstract
  4. AEMPS. Urea C13. Ficha técnica. 2004 Full text (in our servers)
  5. Isomed. Urea-C13. Ficha técnica 2001 Full text (in our servers)
  6. Wheeler RA, Jackson AA, Griffiths DM. Urea production and recycling in neonates. J Pediatr Surg. 1991 Abstract
  7. Ross SA, Clark RM. Nitrogen distribution in human milk from 2 to 16 weeks postpartum. J Dairy Sci. 1985 Abstract

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