Growth hormone arrives in bursts, mostly while you sleep. And unlike almost every other hormone on this site, raising it is not obviously a good idea.
How GH and IGF-1 relate, why a single GH measurement is nearly meaningless, and the genuine tradeoff between growth signaling and long-term health.
Growth hormone is released by the pituitary in sharp pulses rather than continuously, and the largest of them occur during deep sleep early in the night. It is one of the more direct links between the sleep school and this one.
Much of what GH does, it does indirectly. It instructs the liver — and local tissues — to produce IGF-1, which carries out many of the downstream effects.
A measurement problemBecause GH comes in bursts, a random blood sample may land on a peak or in a trough. The same person, on the same day, can be measured as high or low depending on the minute. A single random GH level is close to uninterpretable, which is why endocrinology uses stimulation and suppression testing instead.
IGF-1 is steadier, so it is the more practical measure — but it has to be interpreted against age, since it falls naturally across the lifespan, and it is lowered by poor nutrition and liver disease independently of GH.
Beyond heightIn childhood the role is obvious. In adults GH and IGF-1 contribute to body composition, connective tissue and bone maintenance, and metabolic regulation. Genuine adult deficiency is a real medical condition with real consequences, and it is treated.
Levels also fall with age — which is where the marketing begins, and where this lesson has to become careful.
Why more is not obviously betterAlmost everything else on this site is about restoring something toward normal. Growth signaling is different, because the evidence points in two directions at once.
The evidence does not support the simple story that raising GH or IGF-1 is anti-aging. If anything, the longevity evidence points the other way, while the quality-of-life evidence in genuine deficiency points toward treatment. Both can be true, because they are answering different questions about different people.
That is an uncomfortable place to end, and it is the accurate one. A field with a real tradeoff at its center should not be summarized as though it had a direction.
On the products: GH itself is a prescription medicine. Secretagogues and related peptides are discussed here only as general categories — this lesson gives no protocols, sourcing, preparation, dosing or cycling for any of them, and material obtained outside medical supply carries real risks of contamination and incorrect dosing on top of the biological questions above.
The one intervention that genuinely raises GH, costs nothing and carries no risk is the one this lesson opened with: sleeping properly. The largest natural pulses happen in early deep sleep, and short or fragmented sleep reduces them.
GH is secreted in pulses with the largest occurring during early slow-wave sleep; IGF-1 is comparatively stable. Established endocrinology.
A single random GH measurement is not diagnostically useful, which is why stimulation and suppression testing is standard. Clinical practice.
Sustained GH excess causes cardiovascular, metabolic and joint disease and reduces life expectancy. Well documented.
Reduced GH and IGF-1 signaling extends lifespan across multiple model organisms — one of the more reproducible findings in aging biology, though translation to humans is not established.
The optimal IGF-1 level for a healthy adult. Higher levels associate with some cancers, lower levels with frailty in older people — genuinely unresolved rather than merely unclear.
Growth hormone pulses mostly during deep sleep and acts largely through IGF-1 — and unlike most of this site, the evidence on raising it points in two directions at once, which is a tradeoff rather than a recommendation.
Health makes more sense when more than one person is looking at it. Everything here is free to read.
Want the rest? The foundation bundles collect these lessons into one file, free.
A visual guide to how metabolism, mitochondria, hormones, sleep, muscle, the heart, the gut and the brain influence one another — the whole system on one page, with the strongest connections written out. Use it as your roadmap while you work through the lessons.
Free. The map is yours to keep. Plus occasional new lessons and evidence-based updates. No spam. Unsubscribe any time.
Free to download right now — no email needed:
The Health Map — a visual guide to how metabolism, mitochondria, hormones, sleep, muscle, the heart, the gut and the brain influence one another. Every lesson on the site stays free to read either way.
Free. No spam, unsubscribe any time.
