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Growth Hormone (IGF-1) Ratio (Serum)

Published: August 9, 2026Updated: August 17, 2026

This test measures the relationship between your growth hormone levels and insulin-like growth factor 1 (IGF-1) in your blood. It helps assess how well your body is responding to growth hormone over time.

Quick summary

["This ratio helps doctors evaluate growth hormone function and potential growth issues."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
95847-0
Short code
GH 90M p Macimorelin Ser IA-mCnc
Synonyms
GH 90M p Macimorelin Ser IA-mCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
0
Ref high
17
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order this test if you have signs of growth hormone imbalance, such as slow growth in children, muscle weakness, or changes in body composition in adults. It can also be used to monitor treatment for conditions like pituitary disorders or growth hormone deficiency.

What to Expect Before the Test

No special preparation is needed. You’ll have a simple blood draw, usually done in a doctor’s office or lab. You may feel slight discomfort, but it’s brief.

How the Test Works

Blood is drawn and sent to a lab where it’s analyzed to measure both growth hormone and IGF-1 levels. The results are then compared to determine the ratio, which helps assess hormone function.

Possible Results and Next Steps

Results are interpreted by your doctor based on your age, symptoms, and medical history. Abnormal ratios may indicate conditions like growth hormone deficiency, acromegaly, or other hormonal imbalances. Your doctor will discuss next steps, such as further testing or treatment options.

Reference range

NCBI: NSE 0-17 ng/mLN/A

Specimen: serum

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Growth Hormone-IGF-1 Ratio

Frequently asked questions

What does a high or low ratio mean?
A high ratio may suggest growth hormone resistance or overactivity, while a low ratio could indicate insufficient growth hormone production. These findings guide treatment decisions, such as hormone replacement therapy or monitoring for conditions like pituitary tumors.
How often should I get this test?
Your doctor will determine the frequency based on your health needs. For example, children with suspected growth issues may need testing more often, while adults might be monitored less frequently unless symptoms change.
Can lifestyle changes affect this test?
Yes, factors like stress, diet, sleep, and exercise can influence hormone levels. Avoiding extreme stress or significant dietary changes before testing may help get more accurate results.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy