Metabolic
C-Peptide
Unit: ng/mLID: M005
What This Test Measures
Byproduct of insulin production; reflects pancreatic function
Conventional vs. Functional Optimal Range
Conventional "Normal"
0.8-3.1 ng/mLYour doctor says you're "fine" anywhere in this range
Functional Optimal
1.1-2.1 ng/mLThis is where you actually feel great
The gap between these ranges is why you feel terrible with "normal" labs. Conventional medicine waits for disease. Functional medicine optimizes for health.
Gabriel's Take
C-peptide tells you if your pancreas is overworking (high = insulin resistance) or failing (low = Type 1 or burnout). Functional medicine uses this to differentiate insulin resistance from pancreatic exhaustion and monitor progression.
When This Test Is High
Insulin resistance, insulinoma
When This Test Is Low
Low insulin production, Type 1 diabetes, pancreatic failure
Related Conditions
Diabetes type differentiation, pancreatic function
Recommended Follow-Up
If low, check autoantibodies (GAD65, IA-2); if high, address insulin resistance