HGH 191AA
Also known as · Somatropin · rhGH · Genotropin · Norditropin · Humatrope
- EvidenceApproved
- CategoryGrowth hormone
- RoutesubQ
- Half-life~2–3 h (subQ)
01 / Dosing schedule
Cited dosing
The FDA-approved adult GHD schedule offers two approaches: a non-weight-based starting dose of ~0.2 mg/day (range 0.15–0.30 mg/day) titrated by IGF-1 response, or a weight-based initial dose not more than 0.04 mg/kg/week.
Genotropin — adult GHD, non-weight-based
| Phase | Dose & frequency |
|---|---|
| Starting dose | ~0.2 mg/day subQ (range 0.15–0.30 mg/day) |
| Titration | Increase by 0.1–0.2 mg/day every 1–2 months |
| Guided by | Clinical response + age/gender-adjusted IGF-1 |
| Frequency | Once daily (6–7 injections per week) |
Source · FDA label — Genotropin (2014) ↗
Genotropin — adult GHD, weight-based
| Phase | Dose & frequency |
|---|---|
| Starting dose | Not more than 0.04 mg/kg/week subQ |
| Titration | Increase to ≤0.08 mg/kg/week at 4–8 week intervals |
| Divided across | 6–7 subQ injections per week |
Source · FDA label — Genotropin (2014) ↗
Source indication · Adult growth hormone deficiency (Genotropin label).
- Injection frequency
- Once daily, 6–7 injections per week.
- Injection sites
- Abdomen, thigh, or upper arm. Rotate sites to reduce lipoatrophy.
02 / Reconstitution
Reconstitution reference
Research-grade somatropin ships as a lyophilized vial with a supplied diluent. A typical prep is a 10 IU (~3.33 mg) vial with 1 mL bacteriostatic water = 10 IU/mL. At that concentration, a 2 IU dose is 0.2 mL = 20 units on a U‑100 syringe.
03 / Overview
Protocol overview
Somatropin is recombinant human growth hormone (191 amino acid sequence, identical to pituitary GH). It acts directly on GH receptors and drives IGF-1 production in the liver and peripheral tissues.
Adult GHD dosing is orders of magnitude lower than pediatric or bodybuilding-culture doses. The label starts at 0.15–0.30 mg/day (roughly 0.5–1 IU) and titrates by IGF-1, not by feel.
The FDA label emphasizes that maintenance doses vary considerably by patient and gender — women generally require higher doses than men.
Adverse effects at supraphysiologic doses (edema, arthralgia, carpal tunnel, insulin resistance) scale with the dose. The label's slow titration is the primary tool for staying below that threshold.
04 / References