Somatropin (recombinant HGH)
The only compound in this catalog with real dose-ranging trials in growing humans — measured all the way to adult height. The catch: the curve saturates, the highest randomized dose is far below what circulates in gym culture, and the drug spends the very resource it grows you with.
The short version
- Height gain is real and dose-dependent: in short pubertal boys, 67 µg/kg/day added +0.32 SDS of pubertal growth over 33 µg/kg/day — the highest randomized pubertal dose on record. DATA
- In healthy elderly adults the body-composition effect is small: fat −2.1 kg, lean +2.1 kg — with more adverse events, and the authors' verdict that GH “cannot be recommended as antiaging therapy.” DATA
- A high-dose pediatric arm accelerated bone age 1.8× faster than calendar and bought no height-for-bone-age — the dose ceiling exists for a reason. DATA
- GH depletes growth-plate stem cells — the proliferative reserve that plates run on. More hormone spends that reserve faster. DATA
The dose ladder — randomized, to final height
| Trial | Population | Doses | Result |
|---|---|---|---|
| Albertsson-Wikland 2014 | short/pubertal children, randomized to adult height | 33 vs 67 µg/kg/d | pubertal gain +0.41 vs +0.73 SDS — high dose wins; highest RCT-tested pubertal dose |
| Wit 2005 | SGA children, blinded to adult height | 0.24 vs 0.37 mg/kg/wk | +3.6 cm adult height, P=.025 |
| van Pareren 2003 | SGA girls, blinded to adult height | 0.23 vs 0.47 mg/kg/wk | higher dose trended taller; difference not significant |
| Decker 2012 | pharmacometric model, GHSG data | — | height-velocity ED50 ≈ 51 µg/kg/d — half-maximal effect near the standard clinical dose |
How much height, in centimeters
Idiopathic short stature: +4 to +9 cm over predicted DATA
The definitive ISS trial (n=68 pubertal boys, NEJM): +5.0 cm over predicted at final height, +9.2 cm vs untreated controls. The placebo-controlled crossover trial: +3.7 cm adult height. Meta-analysis: +5.3 cm males, +4.7 cm females. That is the whole honest range — single-digit centimeters, in deficient-growing children.
Combination with an aromatase inhibitor adds height in pubertal boys DATA
Open-label RCT in 76 pubertal ISS boys, 24–36 months: near-adult height +18.2 cm (AI) vs +20.6 cm (GH) vs +22.5 cm (AI+GH), P=.01. Plate preservation is the mechanism — see the exemestane page for the AI side and its vertebral-fracture signal.
The ceiling — why more is not more
High dose bought growth rate but stole time: bone age ran 1.8× DATA
The high-dose caution arm (6 IU/m²/d, Kamp 2002): height SDS improved −2.6 → −1.3, but bone age advanced at 1.8× the calendar rate, puberty came earlier, and height-SDS-for-bone-age was unchanged. The drug accelerates the clock it is racing.
Mechanism: GH drains growth-plate stem cells DATA
2025 PNAS lineage tracing in mice: GH stimulation depletes the stem-cell pool of the resting zone — the reserve that keeps the plate growing. Faster proliferation now means fewer divisions available later; the plate's total output is finite and GH spends it. This is the mechanistic mirror of the clinical dose-ceiling above.
Adults: what GH actually does to body composition
Healthy older adults: fat −2.1 kg, lean +2.1 kg, more side effects DATA
The systematic review of the “antiaging” GH literature (18 populations, 220 participants, mean age 69, ~14 µg/kg/d, mean 27 weeks): fat mass −2.1 kg (CI −2.8 to −1.35), lean mass +2.1 kg (CI 1.3–2.9) — with significantly higher rates of edema, arthralgias, carpal tunnel and new diabetes/glucose intolerance. Conclusion verbatim: “GH cannot be recommended as an antiaging therapy.” No strength endpoint improved.
Safety database — the one worth reading twice
French SAGhE: high-dose cohort mortality SMR 2.94 DATA
Long-term follow-up of 6,928 French GH-treated children (mostly idiopathic, doses of the era up to 50+ µg/kg/d): overall mortality raised (SMR 1.33), and in the >50 µg/kg/d group SMR 2.94, bone-tumor SMR 5.0. This is the study behind every “GH causes cancer” headline.
…not confirmed in the 24,232-patient pooled analysis DATA
The same cohort design across Belgium/Netherlands/Sweden (n=24,232, 440,000 patient-years): mortality NOT associated with daily dose or cumulative dose; overall SMR 1.08 (0.97–1.20); 88% of deaths had causes present before GH started. The French signal remains unreplicated — treat it as an open question, not a verdict. Separately: cerebrovascular events did track cumulative dose in one national registry (HR 2.05 highest tertile).
The giant registry: serious adverse events in 3.7% of 83,803 children DATA
KIGS, the largest GH safety database ever assembled: 3,111 SAEs in 83,803 children over two decades — 37 deaths (0.04%), intracranial tumors 0.02%, new malignancies 0.05%. Rare events, not none.
What does not exist
No trial above 67 µg/kg/d with a growth endpoint · no healthy-adolescent trial DATA
Systematic negative (2026-08-28): no controlled trial of GH above 67 µg/kg/d (~0.47 mg/kg/wk) has ever been run with growth as an endpoint, in any population. And no trial in healthy, normally-growing adolescents exists at all. Every dose recommendation beyond the randomized ceiling — including everything in forum use — is extrapolation across a dose range where the one measured mechanism (stem-cell depletion) and the one measured high-dose arm (Kamp) both point the wrong way.