What it measures
Insulin is the hormone made by the pancreas that moves glucose from the blood into cells. The test measures how much is in the blood, usually after fasting.
Why people test it
- Measured with glucose to look at insulin resistance, where the body needs more insulin to control glucose.
- Checked when looking into episodes of low blood sugar.
- Looked at by people with polycystic ovary syndrome, where insulin resistance is common.
Typical range
Ranges vary by lab, method, age and sex, and depend on whether the sample was fasting; your report shows the lab's own range. Labs report insulin in pmol/L or mU/L, so check the unit before comparing results.
Finger-prick or vein?
Taken from a vein, and providers offer it only as a vein draw. Haemolysis lowers insulin results, and finger-prick samples haemolyse more easily.
Insulin is usually measured on a fasting sample, as it rises after eating.