Human Growth Hormone
Recombinant human growth hormone. A 191-amino-acid peptide hormone that stimulates IGF-1 production in the liver, driving fat loss, collagen synthesis, recovery, and modest lean mass gains via indirect anabolic pathways.
Mechanism of Action
Binds the growth hormone receptor and activates JAK2/STAT5 signaling, stimulating hepatic IGF-1 production. Directly increases lipolysis via hormone-sensitive lipase activation in adipocytes. Enhances protein synthesis indirectly through IGF-1 mediated mTOR pathway activation. Stimulates collagen synthesis in tendons and connective tissue. GH effects on lean mass are largely mediated through IGF-1, not direct androgen receptor activation.
Typical Dosing
⚠ Warning Flags
- •Significant insulin resistance at higher doses
- •Potential organ and tissue growth (intestines, heart) with chronic use
- •Ceiling on fat loss per dose — ~1.35 IU subcutaneous maxes out lipolysis per administration
- •Carpal tunnel syndrome, joint pain, and edema are common side effects
Effect Profile
Side Effect Profile
Research Studies
GH effects on body composition in adults
Jorgensen JO et al. · 1989
GH administration decreased fat mass and increased lean body mass in GH-deficient adults, confirming its body recomposition effects.
Growth hormone stimulates the collagen synthesis in human tendon and skeletal muscle without affecting myofibrillar protein synthesis
Doessing S et al. · 2010
GH significantly increases collagen synthesis in muscle and tendon tissue without meaningfully increasing myofibrillar protein synthesis.
Effects of growth hormone on glucose, lipid, and protein metabolism in human subjects
Moller N, Jorgensen JO · 2009
Confirms GH-induced insulin resistance and the metabolic shift toward fat oxidation and protein sparing via the IGF-1 pathway.