Insulin Test
An insulin test measures insulin, the hormone the pancreas makes to help regulate blood sugar. Clinicians often read it alongside glucose to get a sense of how the body is managing its blood sugar rather than as a stand-alone result.
About this test
Insulin is a hormone produced by the pancreas, a gland behind the stomach. When glucose rises in the blood after eating, the pancreas releases insulin, which signals cells throughout the body to take up that glucose and use or store it.
The insulin test is done with a simple blood draw at a patient service center. A phlebotomist collects a sample from a vein, usually in the arm, and the sample goes to the laboratory. Results are read by a clinician in the context of symptoms, history, and any other markers ordered alongside it.
Who might consider this test?
- People who order an insulin test are often looking to understand the hormone side of blood sugar regulation, not just the sugar itself.
- Taking a closer look at their metabolic health
- Following up on questions raised by other markers
Test details
| Quest code | 561 |
|---|---|
| Methodology | Immunoassay |
| Sample type | 1 mL serum |
| Patient preparation | Fast before your blood draw. |
| Collection | Quest patient service center |
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Quest resources
Additional details
What this test looks at
Insulin describes the signal the body sends to manage its blood sugar. While a glucose test tells you how much sugar is in the blood, an insulin test gives a sense of the hormone the body is producing to move that sugar into cells — a different piece of the same picture. Because insulin responds closely to what and when a person eats, the timing of the sample is part of what gives the result meaning.
It also helps to remember what insulin is not: on its own, an insulin value carries limited meaning. That is exactly why a clinician usually reads it alongside glucose and the person's circumstances rather than in isolation.
How it's often used alongside other tests
Insulin is frequently paired with a glucose measurement so the hormone and the sugar it manages can be read together. Depending on the question, a clinician may also consider C-peptide, which reflects the body's own insulin production, or hemoglobin A1c, which reflects longer-term blood sugar patterns. Read together, these markers offer a fuller sense of how the body is regulating blood sugar than any single one can on its own.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does an insulin test measure?
It measures insulin, the hormone the pancreas makes to help regulate blood sugar by signaling cells to take up glucose. A clinician reads it in the context of your history and other markers rather than in isolation.
Why is insulin often measured with glucose?
An insulin value carries more meaning when read alongside the sugar it manages. Ordering insulin together with glucose lets a clinician consider the hormone and the sugar side by side to see how the regulating system is behaving.
Do I need to prepare for this test?
Fast before your blood draw. This is the preparation Quest publishes for this test; if your clinician gives you different instructions, follow theirs.
How is the sample collected?
Through a routine blood draw at a patient service center. A phlebotomist takes a small sample from a vein in the arm and sends it to the laboratory.
Does an insulin test diagnose a blood sugar condition?
No single test diagnoses a condition. An insulin result is one piece of information a clinician considers along with glucose, your history, exam, and other markers to help evaluate how the body regulates blood sugar.
What does a Insulin test cost without insurance?
$35. Celio Health's price is a flat cash price and insurance is never billed: the required physician's order is included.