Growth hormone and liver function are connected through a complex relationship involving hormone production, metabolic regulation and cellular signalling. The liver is a major target of growth hormone (GH), but it is also responsible for producing most of the insulin-like growth factor 1 (IGF-1) found in circulation.
GH influences how the liver processes fatty acids, regulates glucose and responds to metabolic stress. IGF-1 contributes to feedback regulation of GH secretion and has additional effects on non-parenchymal liver cells.
Research into this relationship has become particularly relevant to metabolic dysfunction-associated steatotic liver disease (MASLD), previously described as non-alcoholic fatty liver disease (NAFLD).
Five findings help explain what scientists currently understand about GH–IGF-1 signalling in hepatic physiology.
Why Is the Liver Important to Growth Hormone Signalling?
Growth hormone is released by the anterior pituitary gland and circulates to tissues expressing the growth hormone receptor (GHR).
Hepatocytes, the principal functional cells of the liver, respond to GH through intracellular signalling pathways.
One of the best-characterised pathways involves Janus kinase 2 (JAK2) and signal transducer and activator of transcription 5 (STAT5).
When GH binds to its receptor, JAK2 and STAT5 participate in transmitting signals that regulate gene expression.
These signals influence IGF-1 production and aspects of hepatic lipid and carbohydrate metabolism.
The liver also responds to nutritional conditions, insulin availability and circulating fatty acids. Consequently, the metabolic effects of GH depend on more than hormone concentration alone.
5 Research Findings About Growth Hormone and Liver Function
1. The Liver Produces Most Circulating IGF-1
One of the liver’s most important endocrine functions is producing IGF-1 in response to GH.
GH receptor activation stimulates intracellular signalling that promotes IGF1 gene expression.
The resulting IGF-1 enters circulation, where much of it is carried by IGF-binding proteins.
IGF-1 participates in growth-related signalling and provides negative feedback to the hypothalamic–pituitary system.
However, circulating IGF-1 is not the only form relevant to physiology.
Many tissues also produce IGF-1 locally, allowing tissue-specific responses that may differ from systemic hormone measurements.
This distinction matters when interpreting laboratory studies: a change in circulating IGF-1 does not necessarily describe the full extent of IGF-1 activity in individual organs.
Our growth hormone and IGF-1 research guide examines these signalling differences in more detail.
2. GH Influences Hepatic Fat Accumulation
The liver regulates several processes that determine how much fat accumulates within hepatocytes.
These include fatty acid uptake, de novo lipogenesis, fatty acid oxidation and triglyceride export.
De novo lipogenesis refers to the production of fatty acids from non-fat substrates, including carbohydrates.
Experimental studies indicate that normal GH receptor signalling helps regulate these processes.
In animal models, disrupting hepatic GH signalling can increase fat accumulation within liver cells.
Research also suggests that GH–STAT5 signalling influences genes associated with lipid synthesis and fatty acid oxidation.
These findings help explain why reduced GH activity has been examined as a possible contributor to hepatic steatosis.
However, liver fat accumulation is multifactorial. Insulin resistance, adiposity, diet, genetics and other metabolic conditions can also influence its development.
3. Growth Hormone Deficiency Is Associated With Steatotic Liver Disease
Clinical research has identified an association between adult growth hormone deficiency and an increased prevalence of hepatic steatosis.
Some studies involving adults with established GH deficiency have reported greater liver fat accumulation and metabolic abnormalities than in comparison populations.
These observations are biologically plausible because GH influences both hepatic metabolism and systemic body composition.
Nevertheless, the relationship is not necessarily one-directional.
Obesity and metabolic dysfunction can also alter GH secretion.
Researchers must therefore distinguish between clinically diagnosed pituitary GH deficiency and lower GH secretion associated with obesity.
The two conditions are not interchangeable.
A 2025 review in Nature Reviews Endocrinology examined the liver-specific actions of GH and IGF-1 in MASLD and highlighted both direct hepatic effects and indirect metabolic influences.
The evidence supports a meaningful relationship between GH signalling and hepatic fat regulation, but does not establish GH deficiency as the sole cause of steatotic liver disease.
4. GH and IGF-1 Have Different Roles in Liver Inflammation and Fibrosis
Hepatic steatosis involves excess fat accumulation, whereas steatohepatitis includes liver injury and inflammation.
Fibrosis develops when persistent injury stimulates excessive extracellular matrix deposition.
These processes involve several cell populations.
Hepatocytes carry out much of the liver’s metabolic activity, while Kupffer cells participate in immune responses.
Hepatic stellate cells are especially important in fibrosis because their activation contributes to collagen deposition.
Research suggests that GH and IGF-1 influence these processes through partly different mechanisms.
GH receptor signalling affects hepatocyte metabolism and cellular stress responses.
IGF-1 has been studied for its effects on hepatic stellate cells and pathways involved in fibrogenesis.
Experimental findings indicate that IGF-1 can reduce stellate-cell activation under certain conditions.
However, laboratory evidence of altered fibrotic signalling should not be interpreted as proof that manipulating GH or IGF-1 reverses established human liver fibrosis.
The clinical significance depends on disease stage, the intervention studied and the outcome measured.
5. Hepatic GH Effects Depend on Insulin and Nutritional Conditions
The metabolic effects of GH are strongly influenced by the body’s nutritional state.
During fasting, GH secretion can increase while circulating IGF-1 may decrease.
This apparent contrast reflects the importance of nutrient availability and insulin signalling in hepatic IGF-1 production.
Insulin also influences hepatic GH receptor expression and downstream responsiveness.
GH can promote lipid mobilisation from adipose tissue, increasing the availability of circulating free fatty acids.
At the same time, elevated GH activity can reduce insulin sensitivity under some conditions.
These effects illustrate why GH’s role in liver metabolism cannot be classified as uniformly beneficial or harmful.
A reduction in liver fat and a change in insulin sensitivity are different outcomes, and both require direct measurement.
Our growth hormone and fasting article provides additional context for nutrient-dependent GH regulation.
Direct vs Indirect Effects of Growth Hormone on the Liver
A useful distinction in hepatic research is whether GH acts directly on liver cells or changes liver metabolism through another tissue.
| Mechanism | Primary site | Relevance to liver research |
|---|---|---|
| GH receptor–JAK2–STAT5 signalling | Hepatocytes | Regulates gene expression, IGF-1 production and metabolic pathways |
| Adipose tissue lipolysis | Adipose tissue | Changes fatty acid availability to the liver |
| Circulating IGF-1 signalling | Multiple tissues | Influences endocrine feedback and tissue responses |
| Insulin signalling | Liver and other metabolic tissues | Regulates glucose and lipid metabolism |
| Hepatic stellate-cell activity | Liver | Contributes to fibrosis-related processes |
| Nutritional regulation | Multiple organs | Modifies GH secretion and hepatic responsiveness |
This distinction is important because changes in liver fat may result from a combination of direct hepatocyte signalling and wider metabolic changes.
For example, a study that measures only circulating IGF-1 cannot determine whether altered hepatic lipid accumulation resulted from direct GH receptor activity.
What Does Human Research Show About GH and Liver Fat?
Human trials have examined whether modifying the GH axis changes hepatic fat accumulation in selected populations.
Some studies have reported reductions in liver fat following GH-related interventions, including research involving adults with GH deficiency or particular metabolic conditions.
Other research has examined growth hormone-releasing hormone analogues and their effects on hepatic fat.
However, results from these populations cannot automatically be generalised to healthy adults.
Studies also differ in duration, participant characteristics and the methods used to measure liver fat.
Magnetic resonance-based measurements can quantify hepatic fat, while liver biopsy provides different information about inflammation and fibrosis.
A decrease in liver fat does not independently establish improvement in every aspect of liver disease.
There is also no basis for assuming that research peptides affecting GH signalling have equivalent clinical effects to interventions evaluated in controlled trials.
How Should Researchers Measure GH-Related Liver Changes?
Several complementary measurements are useful when studying growth hormone and liver function.
Circulating GH and IGF-1: These help characterise endocrine activity, although GH’s pulsatile secretion complicates interpretation of isolated measurements.
Liver fat measurements: MRI-derived proton density fat fraction and magnetic resonance spectroscopy can quantify hepatic fat accumulation.
Liver enzymes: ALT and AST may provide information about liver injury, but normal values do not exclude significant disease.
Insulin sensitivity: Glucose, insulin and research-specific metabolic assessments help evaluate systemic metabolic responses.
Fibrosis assessment: Elastography, validated non-invasive markers and histology may be used depending on the study design.
Molecular signalling: Experimental studies can examine GH receptor expression, STAT5 activation and genes associated with lipid metabolism.
No single measurement fully describes the relationship between GH signalling and hepatic health.
Why This Research Matters
The liver provides a useful example of how endocrine pathways can produce different effects across tissues.
GH stimulates hepatic IGF-1 production while also regulating metabolic processes through direct receptor signalling.
IGF-1 contributes additional actions that may involve liver cells other than hepatocytes.
These mechanisms are relevant to research into steatosis, insulin resistance, inflammation and fibrosis.
For laboratories exploring peptide-related endocrine pathways, Peptide Lab Direct UK is our featured UK research peptide supplier, offering a specialist platform for compounds used in molecular and laboratory research.
The most useful scientific approach is to evaluate specific pathways and measured outcomes rather than treating changes in GH or IGF-1 as evidence of improved liver health.
Frequently Asked Questions
Does the liver produce IGF-1?
Yes. The liver produces most circulating IGF-1 in response to growth hormone signalling, although other tissues also produce IGF-1 locally.
How does growth hormone affect liver fat?
GH influences hepatic lipid metabolism through direct receptor signalling and indirect effects on fatty acid availability and insulin regulation.
Is growth hormone deficiency associated with fatty liver disease?
Yes. Studies have identified an association between established adult GH deficiency and increased hepatic steatosis, although multiple factors contribute.
What is the GH–STAT5 pathway?
It is a signalling pathway activated by GH receptor activity that regulates gene expression, including pathways involved in IGF-1 production and hepatic metabolism.
Does IGF-1 affect liver fibrosis?
Experimental research suggests IGF-1 can influence hepatic stellate-cell activity, but clinical effects on established fibrosis require further evidence.
Does higher growth hormone always improve liver function?
No. GH effects depend on endocrine status, nutritional conditions, insulin sensitivity and the particular liver outcome measured.
Scientific References
- Kineman RD, del Rio-Moreno M, Waxman DJ. Liver-specific actions of GH and IGF1 that protect against MASLD. Nature Reviews Endocrinology. 2025;21:105–117.
https://www.nature.com/articles/s41574-024-01037-0 - Vázquez-Borrego MC, Del Rio-Moreno M, Kineman RD. Towards Understanding the Direct and Indirect Actions of Growth Hormone in Controlling Hepatocyte Carbohydrate and Lipid Metabolism. Cells. 2021;10(10):2532.
https://pubmed.ncbi.nlm.nih.gov/34685512/ - Growth hormone deficiency and NAFLD: An overlooked and underrecognized link. Hepatology Communications. 2022.
https://pmc.ncbi.nlm.nih.gov/articles/PMC9426379/ - Growth hormone and nonalcoholic fatty liver disease. Scientific review. 2023.
https://pmc.ncbi.nlm.nih.gov/articles/PMC10373851/ - Direct and systemic actions of growth hormone receptor signalling on hepatic glycolysis, de novo lipogenesis and insulin sensitivity, associated with steatosis. 2023.
https://pubmed.ncbi.nlm.nih.gov/37182789/
Research-only notice: This article is intended for scientific education and laboratory research. It does not provide medical advice, treatment recommendations or instructions for administering research compounds.
