Metabolic
Fasting Insulin
Unit: μIU/mLID: M002
What This Test Measures
Insulin levels after 8+ hour fast; marker of insulin resistance
Conventional vs. Functional Optimal Range
Conventional "Normal"
2.6-24.9 μIU/mLYour doctor says you're "fine" anywhere in this range
Functional Optimal
2-5 μIU/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
This is HUGE. Conventional range goes up to 25, but above 5 can signal insulin resistance YEARS before glucose rises. Fasting insulin is one of the earliest warning signs. At 10-15, you're likely insulin resistant even with normal glucose. Single values are noisy and differ between labs, so watch the trend.
When This Test Is High
Insulin resistance, prediabetes, PCOS, metabolic syndrome
When This Test Is Low
Hypoglycemia, adrenal insufficiency, Type 1 diabetes
Related Conditions
Weight gain, diabetes risk, cardiovascular disease
Recommended Follow-Up
Calculate HOMA-IR; check HbA1c, lipids; implement low-carb diet