Human Growth Hormone (HGH) is secreted by the pituitary gland and drives tissue growth, repair, and metabolic function throughout life. After age 30, GH secretion declines approximately 1–2% per year. By 40, most adults have only half the GH output of their peak. By 60, it's roughly 25%.
IGF-1 (Insulin-Like Growth Factor 1) is the primary downstream mediator of GH's effects. Produced in the liver in response to GH stimulation, it drives cellular growth, protein synthesis, and fat metabolism. IGF-1 is measurable in blood and is the primary marker we use to assess GH status.
Clinical studies show that GH-secretagogue peptides (CJC-1295 + Ipamorelin) increase IGF-1 levels by 30–60% in adult patients with age-related GH decline, with effects on body composition, sleep quality, and recovery time measurably superior to placebo.
At Body Symmetry MD, we prefer peptide-based GH optimization over direct HGH injection for most patients because peptides stimulate the pituitary's own natural pulsatile release pattern, which is both safer and produces more physiologically appropriate IGF-1 levels than direct HGH injection.
