When it comes to understanding your body’s blood sugar balance, most people think of insulin — the vital hormone that helps regulate glucose levels. But there’s another important marker that often goes unnoticed: C-Peptide. This small protein, released in equal amounts with insulin, offers powerful insights into how much insulin your body is actually producing — and why that matters for your overall health.The C-Peptide test is a crucial tool for distinguishing between type 1 and type 2 diabetes, evaluating insulin resistance, and monitoring pancreatic function. It measures the amount of C-peptide in your blood or urine, providing a clear picture of your body’s natural insulin production. Since insulin and C-peptide are released in a 1:1 ratio when the pancreas processes proinsulin, C-peptide acts as a reliable marker — especially because it stays in the blood longer than insulin and is not affected by injected or synthetic insulin.This test is especially helpful for people who have been diagnosed with diabetes but need clarity about the type or stage of their condition. It’s also valuable for individuals showing signs of low blood sugar (hypoglycemia), as it can help determine whether excess insulin is being produced by the body (as in insulinoma) or introduced from outside sources. Doctors may also use this test to assess how well the pancreas is functioning after a pancreas transplant or to monitor residual beta-cell activity in long-term type 1 diabetes patients.A high C-peptide level typically indicates that the pancreas is producing a lot of insulin — often seen in type 2 diabetes, insulin resistance, or certain tumors. On the other hand, low levels may suggest type 1 diabetes, advanced type 2 diabetes, or other forms of reduced pancreatic function.The C-peptide test is simple and non-invasive, usually requiring a blood sample and sometimes done alongside glucose or insulin testing for a more complete picture. Whether you're newly diagnosed, managing an ongoing condition, or seeking answers to unexplained symptoms, this test can offer clarity and help guide more effective treatment decisions.