• Fasting for 8–10 hours is usually recommended for an accurate assessment, unless your doctor advises a random test.
• Inform the laboratory team about any medications you are taking, especially insulin or oral diabetes medications.
• Avoid heavy physical activity before the test, as it may influence glucose and insulin levels.
• Follow your doctor’s instructions carefully if the test is part of a stimulated or post-meal evaluation.
• Carry your doctor’s prescription and a valid ID proof at the time of sample collection.
• For repeat testing, maintain consistent preparation conditions for reliable comparison.

The C-Peptide test measures the amount of C-peptide released into the bloodstream as a byproduct of insulin production. Since insulin and C-peptide are produced together, measuring C-peptide helps determine how much insulin the body is naturally producing.

Doctors commonly recommend the C-Peptide test to:

• Differentiate between Type 1 and Type 2 diabetes
• Evaluate insulin production in diabetic patients
• Assess insulin resistance
• Investigate unexplained hypoglycemia (low blood sugar)
• Monitor pancreatic function in certain medical conditions

The test involves collecting a small blood sample from a vein in the arm. The procedure is quick, safe, and minimally uncomfortable. Results are interpreted alongside blood glucose levels and clinical history.

Low C-peptide levels may indicate reduced insulin production, as seen in Type 1 diabetes or pancreatic dysfunction. High levels may suggest insulin resistance or conditions in which excess insulin is produced, such as Type 2 diabetes or certain tumors.