Insulin blood test
In short
A typical adult insulin result is under 20 mIU/L (fasting). A high fasting insulin most often means the body is working harder to keep sugar in range. It is read with glucose drawn at the same time. Always read your result against the range printed on your own report.
The hormone that moves sugar from your blood into cells.
Your pancreas releases insulin to move sugar from your blood into your cells. A fasting insulin test can show whether your body needs extra insulin to keep sugar in range. Doctors read it together with glucose drawn at the same time.
Is my Insulin high or low?
Type your result to see where it sits.
Nothing you type leaves this device.
Typical range
| For | Range | Unit |
|---|---|---|
| Adults · fasting | under 20 | mIU/L |
| Adults · fasting | under 120 | pmol/L |
Typical ranges for adults. Labs differ a little, so the range printed next to your result is the one to go by.
If your Insulin is high
A high fasting insulin most often means the body is working harder to keep sugar in range. It is read with glucose drawn at the same time.
Common reasons
- Eating or drinking before the test
- Insulin resistance, when the body responds less to insulin, often with weight gain
- Pregnancy, especially in the later months
- Steroid medicines and some diabetes medicines
- Less often: a rare tumor that makes too much insulin
If your Insulin is low
A low fasting insulin is common in lean, active people when glucose is in range. It matters more when blood sugar is high at the same time.
Common reasons
- Strong insulin sensitivity, often in lean, active people
- A long fast before the test
- Less often: a pancreas that makes too little insulin, as in type 1 diabetes
- Less often: pancreas damage from long-term inflammation or surgery
What can throw it off
Eating beforehand raises insulin sharply; insulin treatment and high-dose biotin supplements can also distort it.
Questions to take to your appointment
- 1What does my insulin mean alongside my fasting glucose?
- 2Does this point to insulin resistance?
- 3Could my medicines or a non-fasting sample explain it?
Read together with
Doctors rarely read Insulin alone. These usually sit next to it.
Quick answers
What is the insulin blood test?
Insulin: The hormone that moves sugar from your blood into cells. Your pancreas releases insulin to move sugar from your blood into your cells. A fasting insulin test can show whether your body needs extra insulin to keep sugar in range. Doctors read it together with glucose drawn at the same time.
What is a normal insulin level?
For most adults, insulin is typically under 20 mIU/L (fasting). Some countries print it in pmol/L, so check the unit first. Labs differ a little, so the range printed next to your result is the one to go by.
What does a high insulin mean?
A high fasting insulin most often means the body is working harder to keep sugar in range. It is read with glucose drawn at the same time. Common reasons include eating or drinking before the test; insulin resistance, when the body responds less to insulin, often with weight gain; pregnancy, especially in the later months; and steroid medicines and some diabetes medicines. A doctor reads it together with your other results and how you feel.
What does a low insulin mean?
A low fasting insulin is common in lean, active people when glucose is in range. It matters more when blood sugar is high at the same time. Common reasons include strong insulin sensitivity, often in lean, active people; a long fast before the test; less often: a pancreas that makes too little insulin, as in type 1 diabetes; and less often: pancreas damage from long-term inflammation or surgery.
What can affect my insulin result?
Eating beforehand raises insulin sharply; insulin treatment and high-dose biotin supplements can also distort it.
What should I ask my doctor about my insulin?
Questions worth taking to the appointment: What does my insulin mean alongside my fasting glucose? Does this point to insulin resistance? Could my medicines or a non-fasting sample explain it?
What this page can’t do
It reads each number on its own.
Doctors read results together — ALT with AST, ferritin with hemoglobin, TSH with free T4. A pattern says more than any single flag.
It doesn't know you.
Your age, your medicines, how you feel and your last result all change what a number means.
It doesn't remember.
Close this page and your results are gone. That's on purpose: nothing was ever sent to us.
We also make Vita: Health Coach, an app for those parts. It reads your whole report with your medicines and history in mind, answers follow-up questions in plain words, and keeps your reports in one place — for you and for the people you look after.
Vita: Health Coach on the App StoreSources
Stuck on a word? See the medical words. How we choose our sources. More about Vita Health Coach.