HGH (Somatropin)

HGH refers to human growth hormone. In the research-peptide and performance markets it almost always means somatropin - recombinant human growth hormone (rhGH), a 191-amino-acid single-chain polypeptide produced by recombinant DNA technology and identical in sequence to the GH made by the pituitary. Its potency is expressed in both mass and International Units; the current conversion is roughly 3 IU per milligram (so 1 mg is about 3 IU, with older preparations near 2.6-3 IU/mg). It is marketed as approved medicines such as Genotropin, Norditropin, Humatrope, Saizen, and Omnitrope. Unlike most compounds catalogued here, somatropin is an approved drug with a mature clinical evidence base for specific indications: pediatric and adult growth-hormone deficiency, Turner syndrome, Prader-Willi syndrome, small-for-gestational-age children who fail to catch up, short bowel syndrome, and HIV-associated wasting, among others. For these uses it is supported by randomized trials and long-term surveillance. The contrast is the off-label market. GH is widely diverted for anti-aging and athletic or bodybuilding performance, neither of which is FDA-approved. The landmark evidence on healthy older adults found only small changes in body composition alongside more adverse events, and US law specifically prohibits distributing GH for anti-aging or enhancement. GH is also prohibited in sport by WADA at all times. Material sold outside the approved supply chain is labeled for research use only and may be impure or counterfeit. This entry summarizes the published science and community-reported practice for reference only. It is not medical advice and does not endorse non-prescribed human use.