GH (Growth Hormone Peptide)

Growth hormone (GH) is a peptide hormone naturally produced by the pituitary gland. It consists of 191 amino acids and plays a key role in stimulating growth, cell reproduction, and regeneration in humans. Synthetic forms of GH are created through recombinant DNA technology to mimic the natural hormone’s structure and function.

GH is purported to support muscle growth, fat metabolism, and tissue repair. It is also believed to enhance physical performance, increase energy levels, and promote overall vitality by stimulating protein synthesis and cellular regeneration.

The main benefits of Growth Hormone (GH) include improved body composition and enhanced lean body mass. In adults with GH deficiency, GH therapy has been shown to reduce fat mass and increase lean body mass. For example, a systematic review found that GH treatment in adults with GH deficiency reduced weight and body fat while increasing lean body mass ¹. In one study in men over 60, GH administration increased lean body mass by about 8.8 % and decreased fat mass by about 14.4 % ².

GH also supports bone metabolism and skeletal health. Clinical studies indicate that GH and the associated Insulin‑like Growth Factor‑1 (IGF-1) axis promote bone formation and increase bone mineral density in deficiencies and fracture-healing situations ³. Animal research shows that low IGF-1 levels, caused by GH-axis disruption, lead to reduced bone growth and lower bone mass ⁴. Overall, GH supports body composition, bone health, and metabolic function, making it essential for overall musculoskeletal and metabolic wellness.

The main negative side effects of Growth Hormone (GH) include fluid retention and musculoskeletal symptoms. In large observational studies of adults treated for GH deficiency, around 51% reported adverse events and 18.8% of these were treatment-related. The most commonly reported side effects were joint pain (2.6% treatment-related), peripheral edema (3.1% treatment-related), arthralgia, myalgia, paresthesias and carpal tunnel syndrome ⁵, ⁶.

Another key concern is the effect of GH on glucose metabolism and the potential for insulin resistance or onset of type 2 diabetes. In one review of adult GH therapy, elevations in blood glucose and insulin resistance were documented ⁶. Overall, GH can cause metabolic and structural side effects that vary depending on individual response and treatment duration. These findings suggest that GH’s physiological benefits are closely tied to potential risks involving metabolism and tissue function.

Growth Hormone (GH) binds to its receptor (GHR) on target cells, triggering dimerisation and activation of the associated tyrosine kinase JAK2, which phosphorylates the receptor and recruits STAT proteins (particularly STAT5b) that then translocate to the nucleus to regulate gene transcription ⁷. One major downstream effect is stimulation of the production of Insulin‑like Growth Factor 1 (IGF-1), especially in the liver, which mediates many of GH’s growth-promoting and anabolic actions. GH also influences metabolism, promoting lipolysis in adipose tissue via hormone-sensitive lipase (thus increasing free fatty acids) and impairing insulin signalling in peripheral tissues (which affects glucose uptake and utilisation) ⁸.

GH (recombinant human growth hormone, e.g., somatropin) is FDA‑approved for certain medical conditions (e.g., children with GH deficiency, Turner syndrome, Prader‑Willi syndrome, adults with GH deficiency) in the U.S ⁹. In sports, according to the World Anti‑Doping Agency (WADA) Prohibited List, GH (and its analogues/fragments) is included under “Peptide hormones, growth factors, related substances and mimetics” (class S2) and is prohibited at all times (in‑competition and out‑of‑competition) for athletes ¹⁰.