Preferred Sample Type

C-Peptide (Urine)

Specimen Transport

Samples should be posted on the same day of collection using first class post

Sample Preparation

None required

Turnaround Time

5 days

Sample Stability

3 days at room temperature

C-Peptide (Urine)

General Information

Urinary C-peptide measurement, together with measurement of urinary creatinine, may be used to calculate a Urine C-peptide Creatinine ratio (UCPCR).

UCPCR is mainly to be used in patients on insulin treatment to assess endogenous insulin secretion. Its role in patients not on insulin treatment is limited. The principal role of urinary C-peptide is to identify insulin insufficiency, a feature of long term Type 1 diabetes, in insulin treated patients.  Greater than 95% Type 1 diabetes (> 5 year duration) have a UCPCR value < 0.2 nmol/mmol.

Patient Preparation

Sample Collection: 2 hours after eating largest meal of the day, having emptied their bladder before eating (download instruction sheet).

Sample Type: Urine collected in boric acid container.


Please download and complete the UCPCR Requestor form.

Reference Range

Provided by referral laboratory

UCPCR <0.2 nmol/mmol: Severe insulin deficiency

UCPCR 0.2 -0.6 nmol/mmol: Intermediate insulin secretion

UCPCR >0.6 nmol/mmol: Substantial endogenous insulin secretion

C peptide ranges 2 1024x620


Source of Reference Range

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The Trust Laboratories at Heartlands Hospital, Good Hope Hospital and Solihull Hospital were awarded UKAS (United Kingdom Accreditation Service) accreditation to the internationally recognised ISO 15189 standard in May 2015. For a list of accredited tests and other information please visit the test database
Tests not appearing on this scope are either under consideration or in the process of accreditation and so currently remain outside of our scope of accreditation. However, these tests have been validated to the same high standard as accredited tests and are performed by the same trained and competent staff.

For further information contact Louise Fallon, Quality Manager, 0121 424 1235