Insulin
The hormone that moves sugar from blood into cells. Measured to understand how hard your body works to keep blood sugar in range.
Typical reference range
| Range | Unit |
|---|---|
| 2–20 | mU/l |
What Insulin measures
Insulin is a hormone made by the beta cells of the pancreas. Its main job is to move glucose (sugar) out of the bloodstream and into your cells, where it can be used for energy or stored, which is how the body keeps blood sugar within a healthy range. A fasting insulin test measures the level circulating after several hours without food, when the body is at rest and not responding to a recent meal.
Fasting insulin is rarely read on its own. It is often interpreted alongside fasting glucose, and sometimes with HbA1c or a calculated insulin-resistance index such as HOMA-IR, to gauge how hard the pancreas is working to keep glucose normal. Because levels shift with food, stress, and time of day, fasting and clinical context both matter for a meaningful read.
What a high Insulin can mean
A high fasting insulin can suggest insulin resistance, a pattern where cells respond less readily to insulin, so the pancreas releases more of it to keep glucose in a normal range. This is commonly associated with excess weight, metabolic syndrome, and a raised risk of prediabetes and type 2 diabetes.
An important nuance is that insulin can run high while fasting glucose still looks normal, because the extra insulin is compensating and holding sugar steady, which is one reason clinicians may look at insulin alongside glucose rather than glucose alone. Less commonly, other factors can contribute, including certain medications or hormonal conditions.
A single result is best understood as one part of a broader picture. Consider it a pattern to discuss with a clinician, who can weigh it against your glucose, history, and other markers.
What a low Insulin can mean
A low fasting insulin often simply reflects a lean, insulin-sensitive metabolism, where the body needs only a modest amount of the hormone to manage blood sugar well. On its own, a lower level is frequently unremarkable and not a cause for concern.
The interpretation changes with context. When a low insulin appears alongside high glucose, it can point toward reduced insulin production, meaning the pancreas may not be making enough to keep blood sugar in range. This pattern is commonly associated with type 1 diabetes and can also feature in advanced type 2 diabetes as beta-cell output declines.
Because insulin and glucose tell a fuller story together, a fasting insulin is interpreted with glucose, never in isolation. Any result outside the expected range is best reviewed with a clinician, who can add the clinical context needed to make sense of it.
Track your Insulin over time in Quanome — it reads your lab reports (PDF or photo) on your device, charts each marker against its range, and an AI coach explains what your trends mean alongside your Apple Health and DNA.