The Growth Hormone Story. The Hormone Everybody Tried To Buy Is Mostly Produced For Free At Eleven At Night.
Growth hormone has carried the hopes of the anti ageing market for three decades, on the back of a single small trial from 1990 whose caveats were discarded within a few years. The physiology is genuinely interesting. The nightly pulse is real, the age related decline is real, and nothing available on a shelf in this country moves either of them. Here is the honest version.
Opening. The advertisement that arrives after ten
Sarah is thirty four. She trains three days a week, she reads properly, and she has reached the age where the marketing has changed register. It used to sell her a body. Now it sells her time.
The advertisement she sees on a Tuesday night is well made. It explains that a hormone governing repair and renewal falls steadily from your twenties. It shows the curve. It offers a nightly powder of amino acids that will restore youthful levels while she sleeps. There is a word in the name that sounds like a pituitary gland.
Nothing in the advertisement is a lie, exactly. The hormone is real. The decline is real. The curve is roughly the right shape.
What it does not say is that the hormone in question is a prescription medicine in Australia, that it cannot survive being swallowed, that the trial underwriting the entire category is thirty six years old and said something more modest than it is quoted as saying, and that the largest pulse she will produce all day arrives for free about ninety minutes after she falls asleep.
So let us go through it properly, because there is good physiology here and an industry built on one misreading of it.
Section one. What growth hormone actually is
Growth hormone is a protein hormone released by the anterior pituitary, a gland the size of a pea sitting beneath the brain. Its release is governed from the hypothalamus by two opposing signals, one that encourages release and one that restrains it.
Much of what it does, it does indirectly. Growth hormone acts on the liver, which produces insulin like growth factor one, and a good share of the downstream effects attributed to growth hormone are carried by that second molecule. It also acts directly on fat tissue, mobilising fatty acids for fuel, and it participates in protein metabolism, bone remodelling and cartilage growth.
Here is the detail that quietly disposes of most of the marketing. Growth hormone is not a level. It is released in pulses, several across a day, separated by periods where circulating concentrations are very low. A single blood sample taken at a random hour tells you almost nothing, which is why clinicians investigating a genuine deficiency use stimulation testing and look at insulin like growth factor one rather than reading one number off a page.
A pulsatile hormone cannot be meaningfully described as high or low without a protocol. Which means it cannot be meaningfully sold against.
Section two. The night shift
The largest growth hormone pulse of the twenty four hours occurs shortly after sleep onset, in close association with the first episode of deep slow wave sleep.
This is well established. Eve Van Cauter and colleagues at the University of Chicago published extensively on the relationship between sleep architecture and growth hormone secretion, and the pattern is consistent. The pulse tracks slow wave sleep. Shorten the night, fragment it, or push it later, and the pulse is reduced.
Two consequences follow, and they are the practical heart of this article. The first half of the night is where this happens, which makes bedtime more important than wake time for this particular variable. And the decline in growth hormone output across adult life, sometimes labelled somatopause, runs alongside a decline in slow wave sleep across the same decades. The two are not independent.
The age related fall is real. What it means functionally is still argued about, and whether it is a cause of ageing or a feature of it remains open. We made the broader version of this argument in Hormonal Architecture After Thirty. A declining number is not automatically a number to correct.
Section three. Nineteen ninety, and the paper the industry still quotes
In 1990 the New England Journal of Medicine published a study by Daniel Rudman and colleagues. Twelve men over sixty received recombinant human growth hormone for six months. Lean body mass rose. Fat mass fell. The paper reported it carefully.
What the paper did not report is the part that matters. It did not demonstrate improvements in strength, in physical function, or in anything a person would recognise as feeling younger. It was twelve men, it ran six months, and Rudman himself was publicly cautious about how far it should be extended.
Within a few years an entire industry was quoting the lean mass and fat mass figures and leaving the caveats on the floor. Clinics appeared. Books appeared. The phrase about reversing ageing attached itself to a six month study of twelve people, and it has not detached since.
There is a legitimate clinical use for growth hormone, in diagnosed deficiency, under specialist care. That is a different conversation conducted by endocrinologists with proper testing, and it is not what the advertisement on Sarah's phone is about.
Section four. What the following seventeen years found
The question Rudman opened was studied properly, and the answer arrived in 2007.
A systematic review published in the Annals of Internal Medicine by Hau Liu, Andrew Hoffman and colleagues at Stanford pulled together the controlled trials of growth hormone in healthy older adults. The pattern was consistent with Rudman and considerably less exciting. Small changes in body composition. No demonstrated improvement in function or strength that would justify the intervention. And a clear increase in adverse effects, including soft tissue swelling, joint pain, carpal tunnel symptoms and disturbances of glucose handling.
The authors concluded that the evidence did not support growth hormone as an anti ageing intervention in healthy adults. That was nineteen years ago. The category is larger now than it was then, which tells you what you need to know about the relationship between evidence and marketing in this corner of the market.
Two regulatory facts belong here. In Australia, somatropin is a prescription only medicine, and obtaining it outside that channel is both unlawful and unsafe. And growth hormone is prohibited at all times under the World Anti Doping Agency Prohibited List, in and out of competition, which ends the discussion for anyone who competes under a code.
Section five. What is actually in the capsule
Start with the simple part. Nothing you can buy on a shelf in this country contains growth hormone. It is a large protein, it would be dismantled by digestion before it reached the bloodstream, and it is a prescription medicine. Any product described as oral growth hormone is either not growth hormone or should not be for sale.
What these products contain instead is a blend of amino acids and related compounds sold on the premise that they will encourage your own pituitary to release more. Arginine, ornithine, lysine, glycine, gamma aminobutyric acid and sometimes alpha glyceryl phosphorylcholine.
The honest read on each is similar. Oral arginine has the first pass problem we described in The Vascular Floor, where most of an oral dose is intercepted by the gut and liver before it reaches circulation, and the studies looking at arginine and growth hormone around exercise report either no change or a smaller rise than the exercise produced on its own. Gamma aminobutyric acid has one small study, published by Powers and colleagues in 2008, reporting a rise in circulating growth hormone after oral dosing. Whether it reaches the brain in meaningful quantity is debated, and no downstream effect on muscle or recovery has been demonstrated.
Now the argument that matters more than any of the ingredients. Even a product that reliably produced a brief rise would still have everything to prove, because a brief rise is not the mechanism people think it is. Work by Daniel West and Stuart Phillips at McMaster University, and Brad Schoenfeld's reexamination of the hormone hypothesis published in 2013, found that the large acute hormonal responses to a resistance training session do not predict the muscle growth that follows. The spike is a marker of hard work rather than the cause of the adaptation.
So the category is selling a transient change in a pulsatile hormone whose transient changes have already been shown not to be the thing that matters.
Section six. A defensible protocol for the night you actually control
Protect the first half of the night. This is the whole lever. The pulse is tied to deep slow wave sleep, and deep sleep is concentrated early, so a consistent bedtime does more here than a consistent wake time. Our piece on the glymphatic system makes the same case from a different direction.
Hold the schedule within about half an hour, seven nights. Regularity influences sleep architecture independently of duration.
Keep alcohol away from the evening on the nights that matter. Alcohol suppresses slow wave sleep in the first half of the night, which is precisely the window in question.
Keep the last large meal away from bedtime. A substantial carbohydrate load close to sleep raises insulin, and insulin restrains growth hormone release. The mechanism is well described and the practical magnitude is modest, so file this as tidying rather than as a rule worth losing sleep over.
Train hard, and read the response correctly. Resistance training and high intensity work raise growth hormone acutely. That rise is a sign the session was demanding. It is not the reason the session worked, and chasing it is a category error.
Mind the body composition relationship. Higher abdominal adiposity is associated with lower growth hormone output, which is an association rather than a lever, and the useful work is the ordinary work. Our piece on visceral fat covers the territory.
What to spend money on. Protein, because the evidence for adequate protein is as solid as nutrition evidence gets. Creatine monohydrate, because it is the best documented compound in the aisle. Magnesium in the evening, honestly described as supporting sleep and neuromuscular function rather than as a hormonal product. That is the list.
And when to involve a doctor. Suspected growth hormone deficiency in an adult is uncommon, has specific clinical features, and is diagnosed by an endocrinologist using stimulation testing. If something genuinely concerns you, that is the door. Not a powder, and not an article.
Section seven. The mastermind frame
There is a pattern here you will see again, and it is worth learning as a shape rather than as a fact about one hormone.
Find a molecule that declines with age. Publish a small trial. Let the trial be quoted without its caveats for thirty years. Sell a product that cannot contain the molecule, on the premise that it encourages your body to make more, in a system where more was never shown to be better.
Sarah does not need to restore anything. She is thirty four, she trains, and the largest pulse of the hormone in question is produced in her own bedroom every night at no cost, provided she is actually asleep for it.
The hormone you cannot buy is made for free in a dark room. Go to bed at the same time. Train hard enough to deserve the night. The body has been running this schedule for a very long time without help from the aisle.
Frequently asked questions
Do any supplements raise growth hormone?
A few produce small, brief changes in some studies, and gamma aminobutyric acid is the most cited example from one small trial. None has been shown to produce a downstream benefit in muscle, recovery or body composition, and the acute hormonal spike has already been shown not to predict adaptation. Modest mechanism, no demonstrated outcome.
Is fasting a better way to raise it?
Fasting does raise growth hormone, which is a genuine and well documented physiological response to low energy availability. Whether that is useful is a separate question, and for a lifter the costs of prolonged fasting around training usually outweigh an uninterpreted hormone change.
What about peptides that are said to release growth hormone?
Those are not supplements. They are unapproved pharmaceutical compounds in Australia, they are prohibited in sport, and the human safety data is thin. They are outside what we sell and outside what we would recommend, and we will say so plainly in a future piece.
Should I get my growth hormone tested?
Not on your own initiative. A single random measurement of a pulsatile hormone is close to uninterpretable, which is why proper investigation uses stimulation testing ordered by a specialist. If you have symptoms that worry you, start with your doctor rather than with a test you bought.
Does training at night ruin the pulse?
Not in itself. Hard training raises growth hormone whenever you do it. The risk with late sessions is that they push bedtime later and make falling asleep harder, which does affect the nocturnal pulse. If you train late, protect the hour after the session rather than the hour before it.
Written for the Supplement Superstore Vault. We sell the supplements that support the work. We do not sell the work. Information here is educational and is not medical advice. Speak with a qualified health professional before changing any protocol, especially during pregnancy, breastfeeding, competitive training or while managing any clinical condition.
