Growth hormone and IGF-1

growth hormone test · GH test · somatotropin · IGF-1 · somatomedin C

This blood test checks growth hormone and a substance it helps the body make. The second one gives a better idea of your average growth hormone level.

In children, if a child is growing more slowly than other kids. In adults, if hands, feet, or facial features get bigger, and for pituitary gland conditions.

⏱ Duration: the blood draw takes a few minutes; results usually come in a few days

Be sure to tell your doctor

If you or your child get growth hormone shots
If you take hormone medicines
If you have diabetes or problems with nutrition
If you were recently ill or lost a lot of weight

How to prepare

Food. Blood is usually taken in the morning on an empty stomach: 8 to 12 hours without food. Plain water is fine. Check with the lab.
Rest. No hard workouts the day before. Sit quietly before the draw. Growth hormone changes with exercise and stress.
Medicines. Do not stop anything on your own. Tell your doctor what you take. They will decide if anything needs to change before the test.
Your child. Tell your child there will be a quick prick. Bring water and a snack for afterward.

What to bring

Your referral or list of tests
Your ID
Your child's height records over the years, if you have them
Past hormone test results

How it goes

You sit down and rest your arm on the armrest
A band is tied above your elbow, and you are asked to clench your fist a few times
The skin is wiped with antiseptic
A quick prick. Blood fills the tubes in a few seconds
The needle comes out, and a cotton pad is pressed on the spot

What you'll feel

A quick prick, like a pinch
Sometimes slight dizziness. Tell the nurse, and they will help you lie down
A child may get scared. Sit close and hold their hand

Afterwards

Press the cotton pad for 3 to 5 minutes
You can eat right away
Sometimes the doctor needs extra tests with a medicine. That is a separate test

Contact a doctor straight away if

The puncture site is very swollen, painful, and red

Common questions

Why is growth hormone alone not enough?

It is released in bursts, so one sample says little. IGF-1 is more stable, so they are checked together.

Does a low result mean my child needs shots?

No. An endocrinologist, a hormone doctor, decides after a full checkup.