IGF-1 blood test in Chiswick

What the test measures

Insulin-like growth factor 1 (IGF-1) is a hormone made mainly by the liver in response to growth hormone, which is released by the pituitary gland at the base of the brain. Growth hormone is released in pulses through the day and night, so a single reading of it is hard to interpret. IGF-1 stays more stable, which makes it a practical way to estimate average growth hormone activity.

IGF-1 supports growth in childhood and helps maintain muscle, bone and tissue repair in adults. Levels naturally fall with age and are affected by nutrition, liver health and other hormones, so results are always compared with ranges for your age and sex.

The price includes the blood sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result with you, and a GP feedback report on request.

Who it is for

• Your clinician has raised a question about growth hormone levels and suggested an IGF-1 test.
• You have symptoms your practitioner wants to explore, such as changes in hand or foot size or facial features.
• You have had pituitary surgery or treatment and are being monitored by your specialist team.
• You want to understand your result alongside other hormone tests, with a practitioner.

Understanding your result

Your report shows your IGF-1 value with an age-related reference range. A raised IGF-1 can occur with excess growth hormone, which in adults is a rare pituitary condition called acromegaly, and can also be seen in pregnancy and adolescence. A low IGF-1 can reflect reduced growth hormone, but more commonly it is linked with undernutrition, liver disease, an underactive thyroid, poorly controlled diabetes or older age.

IGF-1 cannot diagnose a growth hormone disorder on its own. Specialist dynamic tests are needed to confirm one, usually in an endocrinology clinic. A value outside the range is a prompt for discussion with your practitioner and referral to your GP where appropriate.

Preparing for your test

Fasting is not usually required, but a morning sample after a light breakfast or an overnight fast can give a more consistent reading, and we will confirm what suits you when you book. Tell us if you take oral oestrogen, such as the pill or HRT tablets, steroids or any growth hormone or peptide products, as these affect IGF-1. Avoid high-dose biotin for 48 hours before testing.

IGF-1 is part of the growth and repair markers in Omnia Signature. If you are reviewing other hormones, see Thyroid Function Check. You can also compare every blood test and price in Chiswick.

Questions

How much is an IGF-1 test in Chiswick?

An IGF-1 blood test at Omnia Lifestyle costs £99. This includes the sample at our Chiswick clinic, laboratory analysis, a practitioner review of your result and a GP feedback report on request.

Why test IGF-1 rather than growth hormone?

Growth hormone is released in pulses, so a single reading can be misleading. IGF-1 is steadier and reflects average growth hormone activity.

Does IGF-1 fall with age?

Yes. Levels are highest in adolescence and decline through adulthood, which is why your result is compared with a range for your age.

Can IGF-1 diagnose acromegaly?

It is an important first test, but acromegaly is confirmed with specialist tests in hospital. A raised IGF-1 is a reason for further assessment, not a diagnosis.