Does my growth hormone decline with age, and does that matter?
Your growth hormone does indeed decline sharply with age. Reversing that with hormone injections offers little benefit in healthy older adults and carries health risks, including an increased risk of cancer.
Yes, your growth hormone drops substantially as you get older. In people over sixty, daily values often fall below the detection threshold, comparable to patients who have a genuine deficiency due to a pituitary disorder. This ageing process even has a name: the somatopause. At an advanced age you retain only about twenty percent of what you had during puberty.
That decline is not without consequences. Growth hormone, together with the growth factor IGF-1, drives the building of muscle and bone. Lower levels are associated with loss of bone density and muscle mass. Whether the hormonal drop is the cause or simply runs alongside the broader ageing process has not yet been definitively established. But the association is consistent enough to take seriously.
Can you turn back the clock with hormone injections? Barely, and not without risk. Studies in healthy older adults show at most a modest increase in lean body mass, but no real improvement in muscle function or quality of life. Most of those studies also lacked a placebo group, which further weakens the findings. On top of that, higher IGF-1 levels in large population studies are associated with an increased risk of several forms of cancer1,2,3,4,5.
Animal research even points in a surprising direction. Mice with a hereditary growth hormone deficiency live significantly longer than their normal counterparts. Mice in which the growth hormone gene has been made extra active age faster and live shorter lives. In humans the findings are contradictory, but this makes clear that lower growth hormone activity in later life is not necessarily something that needs to be fixed.
Growth hormone treatment in adults is only medically meaningful when a proven deficiency exists due to a disorder of the pituitary or hypothalamus. The normal age-related decline does not fall into that category. Are you concerned about muscle loss or bone density? Strength training and good nutrition have a better benefit-to-risk ratio than hormone supplementation without a medical indication.
Based on multiple human studies and animal research (PMID 8300054, 36948778, 10905380, 33068640, 9704566). The association between ageing and the decline of growth hormone is well documented. The evidence for the effect of growth hormone treatment in healthy older adults is limited by small sample sizes and the absence of placebo groups.