Growth hormoneGH · hGH · Somatotropin
A pituitary hormone supporting growth, repair and fat metabolism, released mainly during deep sleep.
Growth hormone is released in pulses by the pituitary gland, with the largest pulses during slow wave sleep and smaller ones after intense exercise and during fasting. In children it drives growth; in adults it influences body composition, tissue repair and metabolism.
Much of what it does is indirect, mediated by IGF-1 produced by the liver in response to it and locally in muscle in response to loading. That is why IGF-1, which is stable in the blood, is what clinicians measure, while growth hormone itself is released in bursts and nearly uninterpretable from a single sample.
Its reputation as an anti-ageing treatment does not survive the evidence. A systematic review of growth hormone in healthy older adults found small changes in body composition, roughly two kilograms of lean mass gained and a similar amount of fat lost, with no demonstrated improvement in strength or function, and a high rate of adverse effects including soft tissue swelling, joint pain, gynaecomastia and impaired glucose tolerance.
That combination, cosmetic changes in composition without functional benefit and with real side effects, is why it is not recommended for age related decline and why prescribing it for that purpose is restricted in many countries.
The supplement version is weaker still. Products marketed as growth hormone boosters, typically amino acid blends, either fail to raise it meaningfully or raise it transiently within the normal range, which the evidence above suggests would not matter anyway.
Genuine deficiency is a real diagnosis with real treatment, made with dynamic testing rather than a single level, and it is a different situation entirely from wanting more of it.
In practice, the reliable ways to support your own growth hormone release are sleep and hard training, both of which do a great deal else besides.