HGH (Human Growth Hormone), also called somatotropin, is a 191-amino acid polypeptide hormone produced and secreted by somatotroph cells in the anterior pituitary gland. It is the master regulator of growth, body composition, and metabolism throughout life. HGH signals through the GH receptor (GHR) to activate JAK2/STAT5 signalling, stimulating hepatic IGF-1 production, promoting lipolysis in adipose tissue, and driving protein synthesis in muscle.
How does HGH work?
HGH works via GH receptor binding: two GH molecules bind a single GHR dimer → JAK2 kinase activation → STAT5b phosphorylation → nuclear translocation → IGF-1 gene transcription in the liver. This produces circulating IGF-1, which mediates most of HGH’s anabolic and growth effects via IGF-1R/mTOR/S6K1. Directly, HGH also activates hormone-sensitive lipase for lipolysis, promotes nitrogen retention, and stimulates immune function.
What is the difference between HGH and IGF-1?
HGH (191 AA) is produced by the pituitary and signals through GHR. It stimulates the liver to produce IGF-1, which mediates most anabolic effects. IGF-1 LR3 (83 AA) is a synthetic IGF-1 analogue that directly activates IGF-1R. Research distinction: HGH → upstream axis stimulus (pituitary/liver pathway); IGF-1 LR3 → direct receptor-level anabolic activation. They operate at different points of the same axis.
What is HGH used for in research?
HGH research applications: GH axis biology (GHR, JAK2/STAT5, IGF-1 axis), body composition research (lipolysis, lean mass, adipose tissue metabolism), anabolic biology (muscle protein synthesis, satellite cell activation), bone metabolism (osteoblast activity, IGF-1 bone effects), GH deficiency models, and aging research (GH axis decline with age — somatopause).
Where can I buy HGH for research?
Research-grade HGH (somatotropin) is available from QSC (qscpeptide.com) at ≥99% HPLC purity with Janoshik COA. US Domestic Warehouse: 2–4 business day delivery. Available in multiple IU configurations (36 IU and 100 IU vials). All products sold strictly for in vitro laboratory research only.
What is HGH purity and how is it measured?
Research-grade HGH purity is measured by RP-HPLC (reverse-phase HPLC) and SE-HPLC (size-exclusion HPLC) to detect both purity and oligomeric forms. ≥99% purity by RP-HPLC is the research standard. Mass spectrometry confirms the 191-AA sequence. QSC provides Janoshik-verified COAs. For HGH, SE-HPLC is particularly important — it detects dimers and aggregates that RP-HPLC alone may miss.
How does HGH compare to peptide secretagogues like Ipamorelin?
HGH (exogenous): direct GHR activation, bypasses pituitary feedback, suppresses natural GH secretion via negative feedback. Ipamorelin (GHS-R1a agonist): stimulates pituitary to release endogenous GH in pulses — more physiological pattern, preserves the pulsatile axis, no direct GHR activation. Research choice: HGH for direct GHR/IGF-1 axis studies; Ipamorelin for GHS-R1a biology and pulsatile GH research.
What is somatotropin?
Somatotropin is the scientific name for human growth hormone (HGH) — a 191-amino acid, single-chain polypeptide with two disulfide bonds. The terms are interchangeable. Pharmaceutical HGH (Norditropin, Genotropin, etc.) and research-grade somatotropin from suppliers like QSC both refer to the same 191-AA sequence, produced via recombinant DNA technology (E. coli or mammalian cell expression systems).
What is HGH half-life?
HGH has a serum half-life of approximately 15–20 minutes for the monomeric form. Despite this short half-life, downstream IGF-1 effects persist for 12–24 hours. This short half-life drove the development of GH secretagogues (Ipamorelin, CJC-1295) and long-acting GH analogues (somapacitan, MOD-4023) for research protocols requiring sustained GH axis activity.
What is HGH storage?
Lyophilised HGH powder: store at 2–8°C (refrigerated), not frozen. Reconstituted: store at 2–8°C, use within 14–21 days. Use bacteriostatic water for multi-dose vials. HGH is sensitive to agitation — swirl gently, do not shake or vortex. Avoid freeze-thaw cycles. QSC ships with cold pack.
Where to Buy Research-Grade HGH
≥99% HPLC · Janoshik COA · US Domestic 2–4 Days · Research Use Only
