What Is HGH 191AA?
HGH 191AA refers to recombinant human growth hormone — a 191-amino-acid protein identical to the somatotropin produced by the anterior pituitary gland. FDA-approved forms (Humatrope®, Norditropin®, Genotropin®) are prescription drugs used to treat growth hormone deficiency.
How It Works
Growth hormone binds to GH receptors on cell surfaces, activating the JAK2-STAT5 signaling pathway. This triggers the liver to produce IGF-1 (Insulin-like Growth Factor 1), which mediates most of GH's downstream effects on tissue growth, protein synthesis, and lipid metabolism.
Regulatory Status
FDA-approved as a prescription drug for growth hormone deficiency, Turner syndrome, chronic kidney disease, and Prader-Willi syndrome. Off-label use or distribution outside of legitimate medical prescriptions is a federal crime under the 1990 Anabolic Steroids Control Act. Research-grade somatotropin is used as a reference standard in binding assays.
Cited Sources
- According to Ranke, M.B. & Wit, J.M. (2018). "Growth hormone — past, present and future." Nature Reviews Endocrinology, 14, 285-300. [PubMed]
- According to Møller, N. & Jørgensen, J.O. (2009). "Effects of growth hormone on glucose, lipid, and protein metabolism." Endocrine Reviews, 30(2), 152-177. [PubMed]