What Is HGH (Somatropin)?
Human Growth Hormone (HGH), also known as somatropin or somatotropin, is a 191 amino acid single-chain polypeptide hormone naturally produced by the anterior pituitary gland. Recombinant HGH (rhGH/somatropin) is bioidentical to endogenous growth hormone and is FDA-approved for growth hormone deficiency in children and adults, as well as several other conditions. The '191aa' designation refers to its complete 191 amino acid structure, distinguishing it from older 192aa formulations. HGH regulates growth, metabolism, body composition, and numerous physiological processes through direct actions and via stimulating IGF-1 production.
Mechanism of Action
Binds GH receptors, activates JAK2-STAT5 pathway. Direct effects: lipolysis, protein synthesis. Indirect effects via IGF-1: growth, cell proliferation, anabolism. Half-life ~3 hours subcutaneously.
Key Benefits
Improved body composition (fat loss, lean mass gain), enhanced bone density, better lipid profile, increased energy and recovery, improved skin/hair, better quality of life
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- Long-term Safety of Growth Hormone in Adults With Growth Hormone Deficiency: Overview of 15,809 GH-Treated Patients
Johannsson G, Bidlingmaier M, Biller BMK, et al., 2022, J Clin Endocrinol Metab - Evaluation and Treatment of Adult Growth Hormone Deficiency: An Endocrine Society Clinical Practice Guideline
Molitch ME, Clemmons DR, Malozowski S, et al., 2011, J Clin Endocrinol Metab - Long-term efficacy and safety of somatropin for adult growth hormone deficiency
Götherström G, Bengtsson BÅ, Bosaeus I, et al., 2005, Clin Endocrinol (Oxf) - Impact of growth hormone (GH) treatment on cardiovascular risk factors in GH-deficient adults: a meta-analysis of blinded, randomized, placebo-controlled trials
Maison P, Griffin S, Nicoue-Beglah M, et al., 2004, J Clin Endocrinol Metab - The interaction between growth hormone and the thyroid axis in hypopituitary patients
Behan LA, Monson JP, Agha A, 2011, Clin Endocrinol (Oxf) - Effects of Growth Hormone on Glucose and Fat Metabolism in Human Subjects
Jørgensen JO, Møller L, Krag M, et al., 2007, Endocrinol Metab Clin North Am - Adult Growth Hormone Deficiency - Benefits, Side Effects, and Risks of Growth Hormone Replacement
Reed ML, Merriam GR, Kargi AY, 2013, Front Endocrinol (Lausanne) - Human growth hormone: 1974-1981
Li CH, 1982, Mol Cell Biochem - Topical Delivery of Cell-Penetrating Peptide-Modified Human Growth Hormone for Enhanced Wound Healing
Nguyen TV, Lee KH, Huang Y, 2023, Pharmaceuticals (Basel) - Thiol-Disulfide Exchange in Human Growth Hormone
Chandrasekhar S, Moorthy BS, Xie R, 2016, Pharm Res - A novel peptide antagonist of the human growth hormone receptor
Basu R, Nahar K, Kulkarni P, 2021, J Biol Chem - Structural variants of human growth hormone: biochemical, genetic, and clinical aspects
Chawla RK, Parks JS, Rudman D, 1983, Annu Rev Med