What this marker measures
IGF-1 is the most useful single test for screening growth-hormone disorders. Diagnosis usually requires confirmation via dynamic testing (e.g. oral glucose suppression for acromegaly).
High or low: what it can mean
High IGF-1
Elevated IGF-1 is the principal screening finding in acromegaly (GH excess in adults) and gigantism (in children). It can also rise with certain pituitary tumours.
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Low IGF-1
Low IGF-1 may indicate GH deficiency, malnutrition, poorly controlled diabetes, or liver disease. Age-appropriate interpretation is essential — IGF-1 naturally declines with age.
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Frequently asked questions
What is IGF-1?
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IGF-1 is produced primarily by the liver in response to growth hormone (GH). Because GH levels fluctuate rapidly, IGF-1 — which is more stable — is the preferred marker for assessing overall GH activity.
What does IGF-1 measure?
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IGF-1 is the most useful single test for screening growth-hormone disorders. Diagnosis usually requires confirmation via dynamic testing (e.g. oral glucose suppression for acromegaly).
What does high IGF-1 mean?
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Elevated IGF-1 is the principal screening finding in acromegaly (GH excess in adults) and gigantism (in children). It can also rise with certain pituitary tumours.
What does low IGF-1 mean?
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Low IGF-1 may indicate GH deficiency, malnutrition, poorly controlled diabetes, or liver disease. Age-appropriate interpretation is essential — IGF-1 naturally declines with age.
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
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Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.