HGH Research & Listing Availability

How it works

Recombinant human growth hormone has one of the longest, best-characterised clinical histories of any biologic drug, beginning with Genentech's 1985 FDA approval of somatrem (Protropin) for paediatric GH deficiency — the second recombinant protein drug ever approved after insulin. The shift from pituitary-derived cadaveric hGH (which was withdrawn worldwide in 1985 after recombinant DNA-derived alternatives became available and after Creutzfeldt-Jakob disease transmission from cadaveric preparations was recognised) to recombinant somatropin is one of the early defining successes of biotechnology. The list of FDA-approved indications has expanded substantially since then to cover the paediatric and adult conditions noted above.[1] The off-label history of HGH is dominated by a single 1990 paper — Daniel Rudman's 12-man, 6-month NEJM study reporting that 0.03 mg/kg three-times-weekly somatropin in healthy men aged 61–81 produced modest gains in lean mass and reductions in adipose tissue, without functional benefit — which the anti-aging industry has cited continuously for 35 years as the foundation for rhGH "rejuvenation" use.[1] The much larger and methodologically stronger follow-up literature, summarised in the Liu et al. 2007 Annals of Internal Medicine systematic review of 31 articles on healthy older adults, found small lean-mass and fat-mass changes consistent with Rudman 1990 but no improvement in strength, exercise capacity, or other functional outcomes, and a measurable rate of adverse events (oedema, arthralgias, carpal tunnel syndrome, glucose intolerance, gynecomastia).[2] On the legal question, U.S. federal law (21 U.S.C. § 333(f)(4)(B)) specifically criminalises the distribution of HGH "for any use in humans other than the treatment of a disease or other recognized medical condition, where such use has been authorized by the Secretary of Health and Human Services" — which explicitly excludes anti-aging, body composition, and athletic-performance use.[2][4] GH binds and dimerises the GH receptor, recruiting and activating JAK2, which phosphorylates STAT5 (the dominant transcriptional effector for IGF1 gene expression in hepatocytes) and contributes to MAPK and PI3K/Akt signalling. The dominant systemic action is hepatic IGF-1 production: serum IGF-1 is the principal mediator of long-bone growth in childhood, of skeletal-muscle protein anabolism, and of most of the body-composition effects attributed to GH. Direct (non-IGF-1-mediated) GH effects include lipolysis (driving the characteristic reduction in adipose mass), insulin antagonism (driving the well-documented glucose-intolerance and diabetes-risk signal at chronic therapeutic doses), sodium retention (driving the oedema and carpal-tunnel signals), and stimulation of lipoprotein lipase. The class I cytokine-receptor signalling means GH is a true mitogenic signal in multiple tissues, which is the mechanistic basis for the well-documented Prader-Willi-syndrome contraindication in the setting of severe obesity / sleep apnoea and for the long-standing theoretical and epidemiologic concerns about GH and IGF-1 in tumour biology.

Active research areas

• Research status & evidence base
  **Human evidence (approved indications):** extensive and well-replicated across 40 years of clinical use. Paediatric GH deficiency, Turner syndrome, and adult GH deficiency are the best-characterised, with Endocrine Society clinical-practice guidelines summarising the evidence base and the IGF-1-titrated dosing approach.[3] **Human evidence (anti-aging use in healthy older adults):** Rudman 1990 (n=21, 12 GH + 9 control, 6 months) is the foundational paper.[1] The Liu 2007 Annals systematic review of 31 studies covering 220 GH-treated and 227 control subjects found a small reduction in fat mass (~2 kg) and a small increase in lean mass (~2 kg), with no improvement in strength, exercise capacity, or other functional outcomes, and increased rates of oedema, arthralgia, carpal tunnel syndrome, gynecomastia, and impaired fasting glucose.[2] **Human evidence (athletic performance):** the dominant published study is Liu et al.'s separate 2008 randomised trial in recreational athletes (n=96), which found no improvement in strength, power, or endurance with 20 days of GH 2 mg/day vs placebo, but increased lean mass and reduced fat mass.[2] **Anti-doping context:** GH is on the WADA Prohibited List year-round (S2 peptide hormones); the IsoForm immunoassay (differentiating recombinant 22-kDa GH from the mixture of pituitary isoforms) and the GH-2000 biomarker test (IGF-1 and N-terminal propeptide of type III procollagen) are the standard detection methods.[5] **Long-term safety:** elevated cancer-specific mortality has been reported in long-term follow-up of childhood-onset GH-treated cohorts (the SAGhE cohort study), with the magnitude of effect contested in the subsequent literature; this remains an active area of post-marketing pharmacovigilance.[2]