Scientific Reference

HGH (Somatropin, 191aa)

Evidence profile: Human Phase 3 evidence

Human Growth Hormone (HGH), also known as somatropin, is a 191-amino acid single-chain polypeptide hormone naturally produced by the anterior pituitary gland. Recombinant HGH (rhGH) is bioidentical to endogenous hormone and is widely used in clinical and research settings for growth hormone deficiency and related conditions. HGH regulates growth, metabolism, body composition, and tissue repair. Its effects are mediated both directly through growth hormone receptors and indirectly via stimulation of insulin-like growth factor 1 (IGF-1), which drives many anabolic and regenerative processes.

Mechanism of Action

HGH binds to growth hormone receptors, activating the JAK2-STAT5 signaling pathway, which promotes protein synthesis, lipolysis, and metabolic regulation. It also stimulates hepatic and peripheral production of IGF-1, which mediates cellular growth, proliferation, and tissue regeneration.

Molecular Information

Type: Single-chain polypeptide hormone
Length: 191 amino acids

Pharmacokinetics

The mean terminal half-life of intravenous GENOTROPIN in normal adults is 0.4 hours, whereas subcutaneously administered GENOTROPIN has a half-life of 3.0 hours in GHD adults. The observed difference is due to slow absorption from the su… The bioavailability of subcutaneously administered somatropin is approximately 80% in both healthy subjects and growth hormone deficient patients. A subcutaneous dose of 5 mg of Omnitrope 5 mg/1.5 ml solution for injection in healthy adu…

Published Research

Efficacy and Safety of Weekly Somatrogon vs Daily Somatropin in Children With Growth Hormone Deficiency: A Phase 3 Study
Deal CL et al. · The Journal of clinical endocrinology and metabolism · 2022 · Clinical
PMID 35405011 — View on PubMed
Weekly Lonapegsomatropin in Treatment-Naïve Children With Growth Hormone Deficiency: The Phase 3 heiGHt Trial
Thornton PS et al. · The Journal of clinical endocrinology and metabolism · 2021 · Clinical
PMID 34272849 — View on PubMed
Comparison between long-acting pegylated and daily recombinant human growth hormone for pediatric growth hormone deficiency a systematic review
Zhang J et al. · Scientific reports · 2025 · Review
PMID 40702077 — View on PubMed
Global trends in recombinant human growth hormone for the treatment of idiopathic short stature: a bibliometric analysis
Ouyang R et al. · Frontiers in medicine · 2025 · Review
PMID 40842547 — View on PubMed
Recombinant human growth hormone for children born small for gestational age: meta-analysis confirms the consistent dose-effect relationship on catch-up growth
Crabbé R et al. · Journal of endocrinological investigation · 2008 · Review
PMID 18475054 — View on PubMed