Peptide / HGH

Somatropin

  • CAS 12629-01-5
  • Formula C990H1529N263O299S7
  • Half-life 2-3 hours (SC)
Chemical structure of Somatropin
PubChem CID 56841709 ↗

Clinical Notes

Mechanism, kinetics, and protocol-relevant pharmacology — reviewed by the editorial pharmacology lead.

191-aa recombinant polypeptide — identical primary sequence to endogenous pituitary GH. Acts on the hepatic GH receptor, driving IGF-1 production; most of the observed clinical effect downstream is IGF-1-mediated, not direct GH action. Short serum half-life (2–3 h) but the signalling cascade persists 12–16 h; once-daily SC dosing is sufficient for steady IGF-1 elevation. Dose-response is non-linear: 2 IU nightly produces connective-tissue and skin remodelling without insulin resistance; 4–6 IU begins to compress fasting insulin and HbA1c; above 6 IU the carpal-tunnel, water-retention, glucose-intolerance profile appears reliably. Long-run protocols require quarterly fasting insulin, HbA1c, and IGF-1 — IGF-1 kept below 350 ng/mL for conservative risk-adjusted dosing. Protocol design prioritises duration over peak: 2 IU x 12 months exceeds 4 IU x 3 months on every documented biomarker.

Chemical Identity

CAS Number 12629-01-5
IUPAC Name Human growth hormone (recombinant somatropin, 191-amino acid polypeptide)
Molecular Formula C990H1529N263O299S7
Molecular Weight 22124 g/mol
Melting Point N/A (protein, degrades above 45) °C
Solubility Soluble in water at physiological pH
Half-life 2-3 hours (SC)

Pharmacological Profile

Aromatisation None
Hepatotoxicity None

Known trade names

  • Genotropin
  • Humatrope
  • Norditropin
  • Saizen
  • ZPtropin
  • Jintropin

Cycles using this compound

External references

Data sourced from peer-reviewed pharmacological literature and authoritative chemical databases (PubChem, DrugBank, ChEBI). Provided for identification and research reference only — not medical advice.