HGH (Somatropin): Research Overview

What is HGH?

Human Growth Hormone (HGH/Somatropin) is a 191-amino acid polypeptide hormone FDA-approved for pediatric and adult growth hormone deficiency, HIV-associated wasting, and other conditions. It provides both direct and indirect (IGF-1 mediated) anabolic effects.

What is HGH researched for?

• FDA-approved for idiopathic and organic causes, Turner syndrome, Prader-Willi syndrome, SGA, Noonan syndrome, SHOX deficiency.
• FDA-approved for childhood-onset or adult-onset causes (pituitary tumors, surgery, radiation, trauma).
• FDA-approved to increase lean body mass and body weight in cachexia.
• Significant fat loss especially abdominal/visceral fat over 1-3 months.
• Increased muscle mass and improved body composition.
• Enhanced exercise recovery and tissue healing.
• Improved skin elasticity, texture, and hair/nail growth.
• Improved energy, sleep, and quality of life.

How does HGH work?

Binds to GH receptors on target tissues, triggering JAK2-STAT5 signaling pathway. Direct effects include lipolysis, protein synthesis, and metabolic regulation. Indirect effects via IGF-1 promote growth and anabolism. Half-life ~3 hours subcutaneously.

References

1. Long-term Safety of Growth Hormone in Adults With Growth Hormone Deficiency: Overview of 15 809 GH-Treated Patients

   Johannsson G, Touraine P, Feldt-Rasmussen U, et al. · The Journal of clinical endocrinology and metabolism · 2022

   15,809 patients from the KIMS database, mean 5.3 years follow-up. Adverse events in 51.2% of patients, treatment-related in 18.8%. No correlation between GH dose and adverse event rate. Supports long-term safety of GH replacement in adults with GHD.

   Controlled clinical trial · PMID 35368070

2. Efficacy and safety of growth hormone treatment in adults with growth hormone deficiency: a systematic review of studies on morbidity

   van Bunderen CC, van Varsseveld NC, Erfurth EM, et al. · Clinical endocrinology · 2014

   Systematic review demonstrating positive effects of GH treatment on cardiovascular disease and fracture risk, improvements in body composition, muscle strength, quality of life, bone mass/density, and lipoprotein patterns.

   Review or meta-analysis · PMID 24750271

3. Cardiovascular Risk in Growth Hormone Deficiency: Beneficial Effects of Growth Hormone Replacement Therapy

   Lanes R · Endocrinology and metabolism clinics of North America · 2016

   GH deficiency is associated with several cardiovascular risk factors that significantly increase cardiovascular morbidity and mortality. GH replacement improves cardiovascular risk factors.

   PMID 27241971

4. Unmasking of central hypothyroidism following growth hormone replacement in adult hypopituitary patients

   Agha A, Walker D, Perry L, et al. · Clinical endocrinology · 2007

   In 84 apparently euthyroid patients, 30 (36%) developed hypothyroidism requiring T4 therapy after starting GH. Highest risk in patients with organic pituitary disease or multiple pituitary hormone deficiencies.

   Early human study · PMID 17201804

Common questions