IGF-1 (Somatomedin)
Private IGF-1 blood test in London for £140.99, measuring one growth hormone-related marker with laboratory results expected in around 1 day.
Turnaround time
1 business day
Biomarkers count
1
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Overview of the IGF-1 Test
The IGF-1 blood test measures Insulin-Like Growth Factor-1, a hormone produced mainly by the liver in response to Growth Hormone released from the pituitary gland.
The test contains 1 biomarker: IGF-1 (Somatomedin).
Growth Hormone is secreted in pulses throughout the day and night, which means a single random Growth Hormone measurement can vary considerably depending on when the sample is taken.
IGF-1 remains considerably more stable over the course of the day and is therefore commonly used as an indirect marker of average Growth Hormone activity.
IGF-1 has important roles in normal growth, tissue development, bone metabolism, muscle biology and several metabolic processes.
In children and adolescents, abnormal IGF-1 levels can form part of the investigation of abnormal growth patterns.
In adults, testing is particularly relevant when Growth Hormone excess or deficiency is being considered.
An elevated age-adjusted IGF-1 result is an important laboratory finding when investigating conditions such as acromegaly, in which excessive Growth Hormone activity results in increased IGF-1 production.
A low IGF-1 result can occur with Growth Hormone deficiency, but it can also be seen with malnutrition, chronic illness, liver disease and other physiological or medical factors.
For this reason, IGF-1 does not diagnose Growth Hormone deficiency or excess by itself.
Age is particularly important because normal IGF-1 concentrations change substantially throughout life. Levels are generally higher during adolescence and early adulthood and decline with increasing age.
Results should therefore be interpreted using the laboratory's age-adjusted reference interval rather than one universal target.
Where Growth Hormone excess is suspected, additional dynamic endocrine testing may be required. Where deficiency is suspected, specialist stimulation testing may also be necessary.
What Does the IGF-1 Test Check?
The test measures a relatively stable hormone produced in response to Growth Hormone and provides useful information about average activity of the Growth Hormone–IGF-1 axis. This test measures 1 biomarker.
IGF-1 (Somatomedin)
Measures Insulin-Like Growth Factor-1, a liver-derived hormone regulated largely by Growth Hormone and used as an important marker when investigating Growth Hormone excess or deficiency.
Who May Benefit From the IGF-1 Test?
IGF-1 testing may be useful when symptoms, physical findings or previous hormone results raise concern about abnormal Growth Hormone activity.
People undergoing investigation for possible Growth Hormone excess - Elevated age-adjusted IGF-1 is an important biochemical marker in the assessment of acromegaly.
People undergoing investigation for possible Growth Hormone deficiency - Low IGF-1 can provide supporting information, although specialist stimulation testing may still be required.
People with known pituitary disease - The Growth Hormone axis can be affected by pituitary tumours, surgery, radiotherapy or other pituitary disorders.
People being monitored after treatment for acromegaly - Serial IGF-1 measurements can help assess biochemical response to treatment.
People receiving prescribed Growth Hormone treatment - IGF-1 may be used to monitor treatment response and exposure under specialist supervision.
Children or adolescents undergoing specialist growth assessment - IGF-1 may contribute to investigation where growth is substantially slower or faster than expected.
Adults with unexplained changes in facial or acral features - Progressive enlargement of hands, feet or facial features can prompt assessment for Growth Hormone excess.
People with a previous abnormal IGF-1 result - Repeat testing can help establish whether the abnormality is persistent.
How to Prepare
Do not start, stop or change prescribed Growth Hormone treatment simply to influence the test result.
The laboratory's age-adjusted reference interval is essential when interpreting IGF-1.
Symptoms and Reasons to Consider the IGF-1 Test
Symptoms and physical features associated with abnormal Growth Hormone activity usually develop gradually, particularly in adults.
Progressive enlargement of the hands or feet - Growth Hormone excess can cause changes in soft tissue and bone.
Increasing ring, glove or shoe size in adulthood - Progressive acral enlargement can be associated with acromegaly.
Changes in facial appearance - Coarsening of facial features can occur gradually with sustained Growth Hormone excess.
Excessive sweating - Increased perspiration is commonly reported in acromegaly.
Persistent headaches with other pituitary symptoms - Pituitary disorders can cause headaches, although this symptom is highly non-specific.
Visual changes alongside suspected pituitary disease - Large pituitary lesions can occasionally affect the visual pathways.
Reduced muscle mass or altered body composition with suspected Growth Hormone deficiency - Adult Growth Hormone deficiency can affect body composition and wellbeing.
Reduced bone density in the context of pituitary disease - Growth Hormone deficiency can contribute to impaired bone health.
Abnormal growth in a child or adolescent - Growth assessment requires paediatric interpretation using age and developmental stage.
These symptoms have many possible causes and should not be attributed to Growth Hormone abnormalities from symptoms alone.
New visual-field loss, severe headache or other neurological symptoms in someone with suspected pituitary disease requires prompt medical assessment.
How to Book Your IGF-1 Test
The IGF-1 blood test can be booked privately through London Blood Tests for assessment of the Growth Hormone–IGF-1 axis.
Choose the IGF-1
Select the individual IGF-1 blood test online.
Select your sample collection option
Choose an in-clinic blood draw or professional home or hotel phlebotomy depending on location and suitability.
Attend your appointment
A trained healthcare professional collects the required venous blood sample.
Laboratory analysis
Your serum is analysed for IGF-1 using an appropriate endocrine laboratory method.
Receive your results securely
Your authorised result is delivered securely and can be reviewed with a GP or endocrinologist where appropriate.
When Will I Receive My Results?
The current expected turnaround for the IGF-1 test is approximately 1 business day after the sample reaches the laboratory.
IGF-1 is an established endocrine blood measurement and can generally be processed relatively quickly.
The sample undergoes analysis, internal laboratory quality control and result authorisation before release.
Turnaround begins from laboratory receipt rather than necessarily from the exact time the blood sample is collected.
Occasional analytical review or specimen issues can extend the expected reporting period.
Where the result is significantly abnormal, additional endocrine investigations may take longer because dynamic Growth Hormone testing follows a different laboratory and clinical pathway.
Understanding Your Results
IGF-1 should always be interpreted according to age-specific laboratory reference intervals.
A result within the age-adjusted range suggests that IGF-1 production is not clearly abnormal at the time of testing.
A raised IGF-1 result can support suspicion of Growth Hormone excess, particularly where compatible clinical features are present.
However, acromegaly is not diagnosed from IGF-1 alone. Further endocrine assessment may include Growth Hormone suppression testing and pituitary imaging.
A low IGF-1 result can occur with Growth Hormone deficiency but may also reflect undernutrition, chronic illness, liver dysfunction and other factors.
A normal IGF-1 does not completely exclude Growth Hormone deficiency in every clinical situation.
Where symptoms and clinical history strongly suggest pituitary dysfunction, an endocrinologist may recommend dynamic stimulation testing regardless of the initial IGF-1 result.
Why Book With London Blood Tests?
London Blood Tests provides private access to IGF-1 measurement for people undergoing Growth Hormone or pituitary assessment.
Stable marker of Growth Hormone activity - IGF-1 varies less through the day than Growth Hormone itself.
Relevant to acromegaly assessment - Elevated IGF-1 is a key biochemical finding in Growth Hormone excess.
Useful in Growth Hormone deficiency investigations - Low values can provide supporting endocrine information.
Relevant to pituitary monitoring - Can complement other pituitary hormone investigations.
Suitable for treatment monitoring - Serial testing can be useful during specialist Growth Hormone or acromegaly treatment.
Fast laboratory turnaround - Results are expected in approximately 1 business day.
Professional phlebotomy - Clinic and appropriate mobile blood collection can be arranged.
Clear pricing - The IGF-1 test costs £140.99.
Private IGF-1 Blood Test in London
London Blood Tests provides private IGF-1 blood testing in London for people requiring assessment of average Growth Hormone activity.
The test costs £140.99 and measures 1 biomarker: IGF-1 (Somatomedin).
Results are expected approximately 1 business day after laboratory receipt.
The result should be interpreted according to age and clinical context and should not be used alone to diagnose Growth Hormone deficiency or acromegaly.