Somatropin (recombinant hGH)
Aliases: Genotropin · Norditropin · Humatrope · HGH
Last verified: 2026-09-23
The short version
Recombinant human growth hormone (191 aa) — approved for pediatric/adult GH deficiency, Turner/Prader-Willi syndromes, HIV wasting. Off-label/abuse: anti-aging and sport.
Identity & type
- Molecular type
- peptide
- Origin
- Recombinant human growth hormone (191 aa) — approved for pediatric/adult GH deficiency, Turner/Prader-Willi syndromes, HIV wasting.
Mechanism of action
GH receptor (JAK2/STAT5) → IGF-1 production (liver + local) → growth, lipolysis, protein anabolism.
Dosing & routes
Official / clinical context
Approved drug — indications, dosing and warnings are defined by the official label. Medical 0.2–1 mg/day SC (per kg); abuse 2–6 IU/day.
Regulator-approved labeling and published study designs — never a recommendation.
Community-reported practice
Medical 0.2–1 mg/day SC (per kg); abuse 2–6 IU/day. Recombinant GH: in deficiency — energy, body composition, skin; in anti-aging/bodybuilding circles: fat ↓, muscle ↑, better recovery, but edema, carpal tunnel and insulin resistance at higher doses.
Unverified self-reports. Not medical advice. Not endorsement.
Expected effects (community)
Recombinant GH: in deficiency — energy, body composition, skin; in anti-aging/bodybuilding circles: fat ↓, muscle ↑, better recovery, but edema, carpal tunnel and insulin resistance at higher doses.
Protocol — official vs community
Official / label
FDA-approved rhGH: weight-based (~0.1–0.3 IU/kg/week) or fixed dosing for approved indications (GH deficiency, Turner, SGA, Prader-Willi, HIV wasting).
- 01Start low (0.1–0.2 IU/kg/week divided into daily SC doses)
- 02Titrate by IGF-1, clinical response and side effects
Duration: Chronic for true deficiency; lifelong.
Dosing philosophy: replace toward physiological IGF-1, not beyond. Titration by IGF-1 is the standard of care.
Community (anecdotal)
2–4 IU SC daily (morning or split), typical gray-market 'anti-aging' dose.
- Cycle:
- 6–12 months or longer.
- Break:
- None — exogenous GH suppresses endogenous production; 'cycling off' does not restore it quickly.
Supraphysiological GH in healthy adults is the classic example of paying cardiovascular and oncologic risk for cosmetic benefit.
Human evidence
Well documented in approved indications; anti-aging use in healthy people is unsupported and risky.
Preclinical evidence
The preclinical phase was completed and submitted to regulators as part of registration; pharmacology and toxicology details are part of the official label.
Known risks
- Edema, carpal tunnel, insulin resistance, arthralgia; acromegaloid changes with abuse.characterized
Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.
Unknowns & evidence gaps
- Real-world data outside controlled trials