Insulin-like Growth Factor 2 (IGF-2): Role, Testing, Tumors, and Growth Patterns
Overview
Insulin like growth factor 2, usually shortened to IGF 2, is a hormone related to growth hormone and insulin like growth factor 1 (IGF 1). It plays a big role in growth before birth and early in life. In adults, IGF 2 is still present but is less central than IGF 1 for day to day growth, muscle, and metabolism.
In clinical practice, IGF 2 is most often discussed in the context of rare tumors that produce IGF 2 and cause low blood sugar, or when a detailed growth factor panel is run together with growth hormone and IGF 1 .
What Insulin-like Growth Factor 2 (IGF-2) is and where it is made
IGF 2 is a peptide hormone that looks and acts somewhat like insulin and IGF 1.
It is produced in many tissues, including the liver, and also acts locally in tissues during growth and repair.
During fetal life it is one of the main growth signals. In adults it continues to circulate but plays a more background role.
What IGF-2 does in your body
Supports growth and development, especially before birth and in early life.
Helps regulate how cells use nutrients for growth, repair, and maintenance.
Interacts with insulin and IGF 1 pathways that affect muscle, fat, and organ tissue.
In rare cases, when overproduced by tumors, can drive inappropriate drops in blood sugar by acting on insulin like pathways.
When testing Insulin-like Growth Factor 2 (IGF-2) makes sense
IGF 2 is not a routine blood test. It may be ordered in:
Workup of unexplained low blood sugar in adults when common causes have been excluded and a tumor source is suspected.
Evaluation of rare tumors that can overproduce IGF 2 and cause so called non islet cell tumor hypoglycemia.
Selected specialist endocrine or research settings where detailed growth factor panels are used.
For most growth, muscle, or height questions, doctors rely more on growth hormone and IGF 1 than on IGF 2.
How to think about high and low IGF-2 patterns
There are fewer standard reference patterns for IGF 2 than for IGF 1, and interpretation is usually done by specialists. This is general information and does not replace a detailed review.
Lower IGF-2 might be associated with:
Some developmental or genetic conditions that affect growth factor production, mainly considered in pediatric or genetic settings.
General undernutrition or severe illness, often along with changes in other growth factors.
Higher IGF-2 might be associated with:
Certain tumors that produce excess IGF 2 and can cause repeated low blood sugar episodes in adults.
Rare overgrowth or tumor related states where IGF 2 is one part of a larger growth factor pattern.
In practice, “high” IGF 2 matters most when it matches symptoms like unexplained low blood sugar and imaging findings.
What can influence your IGF-2 levels
Tumors that produce IGF 2 or related peptides.
Nutrition and overall energy balance, especially in severe undernutrition or systemic illness.
Liver function, since the liver is a major source of circulating growth factors.
Hormonal environment, including growth hormone and insulin related signals.
When to talk to a clinician about Insulin-like Growth Factor 2 (IGF-2)
Most people will never need an IGF 2 test. It is worth a detailed discussion with a clinician when:
You have repeated episodes of low blood sugar without diabetes medications or obvious triggers.
You have a known or suspected tumor and your team is checking multiple hormones to explain symptoms.
Your lab report includes IGF 2 from a specialist panel and the values look abnormal.
An endocrinologist or tumor specialist can explain whether IGF 2 is truly contributing to your symptoms and how it fits with growth hormone, IGF 1, insulin, imaging, and other lab results.
Insulin-like Growth Factor 2 (IGF-2) in one view
Insulin-like growth factor 2 is a growth-related hormone that is most important before birth and usually plays a quiet background role in adults. It is rarely measured and mainly comes up when doctors are looking for tumor-related causes of low blood sugar or doing a very detailed hormone workup. High or low IGF-2 only makes sense when viewed together with IGF-1, growth hormone, insulin, and scans, so any out-of-range result should be interpreted by an endocrinologist rather than used for self-diagnosis or self-treatment.
