In-depth entry
FDA Approved Growth Hormone Axis

Somatropin (HGH)

also known as: rhGH, HGH, human growth hormone, Humatrope, Genotropin, Norditropin, Omnitrope, Saizen, Serostim, Zomacton, HGH 191AA, Jintropin, Ansomone, Hygetropin, Kigtropin

FDA-approved recombinant human growth hormone — the direct hormone replacement, with multiple clinical indications, prescription-only status, and specific federal criminal provisions against off-label distribution.

The 191-amino-acid recombinant form of human growth hormone, produced in E. coli (Genotropin, Humatrope) or mouse-cell expression systems, used to replace deficient GH across pediatric and adult indications and — unlike most drugs — subject to federal criminal penalties for off-label distribution under 21 U.S.C. §333(e).

Mechanism of action

Binds dimerized GH receptors on target tissues, triggering JAK2/STAT5 signaling. Direct effects include lipolysis (adipocyte), gluconeogenesis and insulin antagonism (hepatic), and anabolic effects on muscle, bone, and cartilage. Indirect effects are mediated by hepatic IGF-1 production, which drives most of the somatic growth effects. Exogenous administration suppresses endogenous pulsatile secretion via negative feedback on hypothalamic somatostatin and GHRH neurons.

Primary uses

  • Pediatric and adult GH deficiency
  • Turner syndrome
  • Prader-Willi syndrome
  • Chronic kidney disease in children
  • HIV-associated wasting (Serostim)
  • Short bowel syndrome (Zorbtive)
  • Idiopathic short stature
  • SHOX deficiency
  • Noonan syndrome
  • Off-label: anti-aging, bodybuilding (illegal under federal HGH distribution law)

Typical dosing

0.15–0.7 mg/day once daily (legacy) or weekly (Skytrofa, Ngenla) (subcutaneous)

Pediatric GHD: 0.16–0.3 mg/kg/week divided daily. Adult GHD: 0.15–0.3 mg/day titrated to IGF-1 target. Bodybuilding "anti-aging" community use (2–4 IU/day ≈ 0.66–1.33 mg/day) is illegal under federal law and carries meaningful long-term safety concerns including insulin resistance, carpal tunnel syndrome, and accelerated growth of occult neoplasms.

Regulatory status

FDA-approved for: pediatric GH deficiency, adult GH deficiency, Turner syndrome, chronic renal insufficiency in children, Prader-Willi syndrome, idiopathic short stature, small-for-gestational-age children, SHOX deficiency, Noonan syndrome, short bowel syndrome (Zorbtive, daily high-dose), HIV-associated wasting (Serostim). Brand names include Humatrope (Lilly), Genotropin (Pfizer), Norditropin (Novo Nordisk), Omnitrope (Sandoz), Saizen (Merck), Zomacton (Ferring), Serostim (EMD Serono), Skytrofa (Ascendis, weekly), Ngenla (Pfizer, weekly).

References

  1. [fda-pi] Humatrope (somatropin) Prescribing Information. Eli Lilly.
  2. [fda-pi] Genotropin (somatropin) Prescribing Information. Pfizer.
  3. [fda-pi] Norditropin (somatropin) Prescribing Information. Novo Nordisk.
  4. [fda-pi] Skytrofa (lonapegsomatropin) Prescribing Information. Ascendis Pharma.
  5. [review] Molitch ME, et al. "Evaluation and Treatment of Adult Growth Hormone Deficiency: An Endocrine Society Clinical Practice Guideline." J Clin Endocrinol Metab, 2011;96:1587-1609.
  6. [fda-pi] 21 U.S.C. §333(e). Federal HGH distribution law: specific criminal penalties for off-label distribution.

Related peptides

Tesamorelin

An FDA-approved GHRH analog for reducing excess visceral fat in HIV-associated lipodystrophy.

Sermorelin

The N-terminal 29 amino acids of native GHRH — a former FDA-approved diagnostic and pediatric GH-deficiency therapy, now widely compounded for adult anti-aging protocols.

CJC-1295

A long-acting GHRH analog engineered with a DAC linker that binds serum albumin, extending half-life from minutes to approximately 8 days.

Ipamorelin

A selective ghrelin receptor agonist that stimulates GH release without the cortisol, prolactin, or ACTH spike seen with older GHRPs like GHRP-6.

MK-677

An orally active non-peptide ghrelin receptor agonist — included here by convention because it is universally marketed alongside peptide GH secretagogues. FDA warns of heart failure risk.

IGF-1 LR3

A 13-amino-acid N-terminal extension plus Arg3 substitution gives IGF-1 LR3 roughly 2–3× the potency of native IGF-1 in bioassays — a research-reagent favorite that became a bodybuilding staple despite no human approval.
Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.