HGH

HGH (Human Growth Hormone) Peptide

HGH (somatropin) is a recombinant 191–amino-acid polypeptide identical in sequence to endogenous human growth hormone secreted by the anterior pituitary. It has a nominal molecular mass of ~22 kDa and engages the growth hormone receptor to influence growth, body composition, and intermediary metabolism. In research contexts, potency is expressed in International Units (IU) calibrated to the WHO/Ph. Eur. standard, where 1 mg of anhydrous somatropin is conventionally equivalent to 3.0 IU of biological activity. (1)(2)(3)(4)

Overview

Somatropin binds the growth hormone receptor, inducing receptor dimerization and activation of JAK2/STAT signaling, with downstream transcriptional effects in multiple tissues. Many effects are mediated indirectly via hepatic and peripheral induction of insulin-like growth factor-1 (IGF-1). Investigations have described actions on protein synthesis, lipolysis, carbohydrate and lipid metabolism, fluid balance, and bone remodeling. (5)

International Unit (IU) labeling for somatropin reflects bioactivity rather than mass; the 3 IU = 1 mg convention is used for labeling and comparison across preparations that conform to the WHO standard. (2)(3)

Chemical Makeup

Molecular Weight: ~22,125 Da (monomer, 191 aa)

Molecular Formula: C₉₉₀H₁₅₂₈N₂₆₂O₃₀₀S₇

Other Known Titles: Somatropin; recombinant human growth hormone; rhGH; CAS 12629-01-5

Research and Clinical Studies

Adult Growth Hormone Deficiency (AGHD) and Body Composition

Randomized and controlled studies, systematic reviews, and meta-analyses in adults with confirmed growth hormone deficiency report reductions in total and trunk fat mass with increases in lean body mass during GH replacement. Several analyses also note improvements in lipid variables and patient-reported quality-of-life measures, alongside dose-related fluid retention events. (6)(7)(8)(9)

Dosing Principles in Research Settings

Guidance documents for AGHD emphasize individualized titration guided by IGF-1 targets and clinical responses, recognizing sex- and age-related differences in sensitivity to GH. Lower starting doses with gradual adjustments are commonly described to balance desired biomarker and body-composition endpoints against dose-related adverse effects such as edema or arthralgia. (7)(10)(11)

Mechanistic Notes

Canonical descriptions of GH receptor biology detail JAK2/STAT5 pathway activation, with broader crosstalk to MAPK and PI3K cascades implicated in metabolic and anabolic effects. (5)

HGH (somatropin) is offered for research and laboratory purposes only.

HGH 150iu Peptide is available for research and laboratory purposes only. Please review and adhere to our Terms and Conditions before ordering.

References

1. U.S. FDA – Humatrope (somatropin) label. Identity and product description. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/020280s092lbl.pdf
   
2. USP/Ph. Eur. convention: “Somatropin for Injection” monograph—1 mg anhydrous somatropin ≙ 3.0 IU. https://www.uspbpep.com/ep60/somatropin%20for%20injection%200952e.pdf
   
3. EDQM/WHO standardization note: Specific activity 3.0 IU per mg adopted for somatropin. https://www.edqm.eu/documents/52006/123862/bsp004-somatropin-crs1.pdf/759a6c11-3085-1a6b-ffc4-c53795afb1b6
   
4. FDA – Nutropin (somatropin) label: Example vials showing ~30 IU per 10 mg (3 IU/mg convention). https://www.accessdata.fda.gov/drugsatfda_docs/label/2007/019676s030%2C020522s033lbl.pdf
   
5. Waters MJ, Brooks AJ. “JAK2 activation by growth hormone receptor.” Growth Horm IGF Res 2015 – mechanistic overview. https://www.sciencedirect.com/science/article/pii/S1096637415000180
   
6. Deijen JB et al. / Systematic review (European Journal of Endocrinology): GH replacement decreases fat mass and increases lean mass; QoL signals reported. https://academic.oup.com/ejendo/article-abstract/166/1/13/6659269
   
7. Endocrine Society Clinical Practice Guideline (2011): Evaluation and Treatment of Adult Growth Hormone Deficiency. https://jeffreydachmd.com/wp-content/uploads/2015/04/Evaluation-and-treatment-of-adult-growth-hormone-deficiency-Endocrine-Society-Clinical-Practice-Guideline-Molitch-2011.pdf
   
8. J Clin Endocrinol Metab (2004): GH replacement in adults—changes in body composition and lipids over 12 months. https://academic.oup.com/jcem/article-abstract/89/5/2048/2844165
   
9. Meta-analysis of dose ranges in adult GHD. https://link.springer.com/article/10.1007/s11102-014-0571-z
   
10. AACE/ACE Guideline (2019): Management of adult GHD and transition care. https://pro.aace.com/clinical-guidance/2019-clinical-practice-guideline-management-growth-hormone-deficiency-adults
    
11. Endocrine Society – Guideline hub. https://www.endocrine.org/clinical-practice-guidelines