Growth hormone-releasing hormone
The hypothalamic hormone that switches on growth hormone, first found in a pancreatic tumour
Growth hormone-releasing hormone (GHRH) is a 44-amino-acid peptide from the hypothalamus that tells the pituitary to release growth hormone. It was first isolated in 1982 from a pancreatic tumour that had caused acromegaly. Given by injection it raised growth hormone in children and adults, sped up growth in children lacking it in small studies, and became a diagnostic test with arginine. Its shorter analogues, sermorelin and tesamorelin, have their own entries.
Used in human trials: 10 or 20 µg/kg, Twice daily, Subcutaneous injection (Growth hormone deficiency, prepubertal (20 children)) Details ↓
Recommended Dosing
Used in human trials
No manufacturer dose exists for this use: these are amounts given in published trials, not recommendations.
Work out syringe units → · New to syringes? · All dosing data ↓
What is it?
Growth hormone-releasing hormone, also called somatoliberin or somatorelin, is made in the hypothalamus and carried to the pituitary, where it stimulates the release of growth hormone; somatostatin is its opposing signal. It was identified in 1982 not from the brain but from a human pancreatic tumour that had caused acromegaly: the 44-amino-acid peptide isolated from that tumour matched the releasing factor in hypothalamic extracts, and a synthetic copy had full activity in cells and in animals. A 40-residue form, GHRH(1-40), also occurs naturally. The analogues built from GHRH, sermorelin (its first 29 residues) and tesamorelin, have their own entries with their own trials.
In blood, GHRH is cut quickly. Plasma dipeptidyl peptidase IV removes its first two amino acids, the main step that inactivates it, and trypsin-like enzymes cut it further along; synthetic analogues were later designed to resist these enzymes. We found no human plasma half-life figure for GHRH itself in the abstracts read.
Soon after it was synthesised, GHRH(1-44) was given to large numbers of children with short stature. In 139 normal but short children and 63 with growth hormone deficiency, a 1 or 2 µg/kg intravenous bolus raised growth hormone more than insulin-induced hypoglycaemia did in the normal children; 35 of the deficient children did not respond, while 28 did. A second study used the size of the response to separate a hypothalamic from a pituitary cause of deficiency. Given as a constant infusion, it raised growth hormone at first and then lost effect as the pituitary became less responsive, while repeated boluses kept working.
Treatment trials followed. In 1985 two children with growth hormone deficiency given pulses of GHRH every three hours by pump for six months grew faster, one from 4.6 to 7.1 cm a year and the other from 2.1 to 13.7 cm. In a multicentre study, 20 prepubertal children given GHRH(1-44) twice daily by injection grew at 8.5 cm a year in the first year against 3.6 cm before, with growth sustained for up to four years in five of them and no adverse effects noted. It was never approved as a treatment.
GHRH has also been given to healthy adults. Older men release less growth hormone in response to it than young men; giving it every two days for 12 days restored the response in healthy older men but not in adults with growth hormone deficiency. It also affects sleep: given at night after sleep deprivation it deepened non-REM sleep and lowered cortisol in men and women, while in young women on a normal night it reduced REM and deep sleep.
Its lasting clinical role was as a stimulation test. Combined with arginine, GHRH became an accepted alternative to the insulin tolerance test for diagnosing growth hormone deficiency in adults. A 2025 history of the test records that its production stopped for business reasons, which left a gap in diagnosis. GHRH is also measured in blood to diagnose ectopic acromegaly, a rare condition in which a neuroendocrine tumour, usually in the lung or pancreas, secretes GHRH. In one review of 127 such cases, complete removal of the tumour was the treatment of choice. GHRH is on the World Anti-Doping Agency's prohibited list.
Mechanism of Action
GHRH is released from the hypothalamus into the blood vessels that run to the pituitary, where it stimulates the cells that make growth hormone. Somatostatin works against it.
Growth hormone release
A single intravenous or subcutaneous dose raises blood growth hormone within 15 to 30 minutes in children who can respond.
Desensitisation with constant exposure
During a constant infusion, growth hormone peaked within two hours and then fell despite continued GHRH, and a second bolus produced no rise; separate boluses each worked.
Fast breakdown in blood
Dipeptidyl peptidase IV removes its first two residues and trypsin-like enzymes cut it further, the steps that analogue designs set out to block.
Sleep and the stress axis
Night-time GHRH promoted non-REM sleep and lowered cortisol after sleep deprivation, but impaired sleep in young women on an ordinary night.
Published Research
Studies of GHRH itself, read from their PubMed abstracts: its 1982 isolation, tests and treatment studies in children, studies in adults, and reviews of its diagnostic use. Trials of sermorelin, tesamorelin and other analogues study different molecules and are carded on their own entries.
Isolated from an acromegaly tumour
A 44-amino-acid peptide with growth hormone-releasing activity was isolated from a human pancreatic tumour that had caused acromegaly; the synthetic replicate had full activity in vitro and in vivo and matched the releasing factor in hypothalamic extracts.
A test in 202 children
In 139 normal short children, a 1 or 2 µg/kg intravenous bolus raised growth hormone to a mean peak of about 32 ng/ml, more than insulin hypoglycaemia; 35 of 63 children with growth hormone deficiency did not respond, while 28 rose above 5 ng/ml.
Hypothalamic or pituitary deficiency?
In 23 children with total or partial growth hormone deficiency and 7 short controls, a 2 µg/kg intravenous dose gave variable responses; a peak above 10 ng/ml suggested a hypothalamic cause in 12 patients.
Under the skin, once and for five days
A 100-200 µg subcutaneous dose raised growth hormone to a mean peak of 27 ng/ml at 15 minutes in eight normal short children; 8 of 11 deficient children did not respond, and 200 µg twice daily for 5 days restored a response in 2 of 8.
Constant infusion loses effect
In short boys, a 2.5 µg/min infusion raised growth hormone to a peak at 60-120 minutes, after which it fell despite continued infusion; a second bolus during infusion gave no rise, while two separate boluses each did.
Faster growth in two children
Two children with growth hormone deficiency given 1-3 µg/kg subcutaneously every 3 hours by pump for 6 months retained nitrogen, raised somatomedin C in one, and grew faster: from 4.6 to 7.1 cm a year and from 2.1 to 13.7 cm a year.
Up to four years of treatment
Twenty prepubertal children with classical growth hormone deficiency given GHRH(1-44) 10 or 20 µg/kg twice daily grew 8.49 cm in year 1 against 3.57 cm before, and about 6.2 cm a year in years 3 and 4 (five children); IGF-I stayed normal and no adverse effects were noted.
Ageing and a priming course
Older men had a smaller growth hormone response to GHRH(1-40) than young men; 100 µg intravenously every 2 days for 12 days, against placebo in a double-blind design, restored a larger response.
Priming works in ageing, not deficiency
The same 12-day priming course (100 µg every 2 days) raised the growth hormone response to a GHRH test in seven healthy older men but not in four adults with growth hormone deficiency.
Sleep after sleep deprivation
In 48 women and men aged 19-67, repeated GHRH during the recovery night after 40 hours awake increased non-REM sleep and decreased wakefulness more than placebo, raised growth hormone and lowered cortisol, with no sex difference.
Sleep in young women
In healthy young women studied early in the menstrual cycle, four intravenous pulses of 25 or 50 µg GHRH reduced REM sleep or deep sleep against placebo and raised growth hormone, with ACTH and cortisol unchanged.
The history of the GHRH test
GHRH alone gave poorly reproducible results, so it was combined with arginine or growth hormone secretagogues; the GHRH plus arginine test entered practice, and the end of GHRH production for business reasons opened a gap in diagnosing deficiency.
127 cases of ectopic acromegaly
Ectopic acromegaly is mostly caused by GHRH from neuroendocrine tumours of the lung and pancreas; diagnosis needs tumour staining or a plasma GHRH level, and complete resection is the most effective treatment.
Ectopic GHRH: 30 years on
Plasma GHRH above 250 to 300 ng/L is highly specific for ectopic secretion and tracks recurrence after surgery; somatostatin analogues control growth hormone but only partly reduce GHRH.
How plasma breaks it down
In plasma, dipeptidyl peptidase IV cleaves native GHRH(1-44) and (1-40) between residues 2 and 3, and trypsin-like enzymes cut at 11-12; D-amino acid substitution at position 1 or 2 prevented the first cleavage.
Dosing Data
The amounts below are the doses of GHRH(1-44) given in the published studies carded above, as treatment in children and as a test. No GHRH(1-44) product is approved, so there is no label dose.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no label and no published test that says what forms or vial sizes Growth hormone-releasing hormone is sold in. A vial's own label is a seller's claim, not a source.
Mixing a vial: a worked example
No worked example: none of the doses on this page is a fixed amount in mg or mcg injected under the skin or into a muscle (the routes given are: intravenous, subcutaneous, subcutaneous injection). There is no home-mixing step to show. The reconstitution calculator does the arithmetic for any vial.
Source: the route and amount of each dose row in Dosing Data below.
Storage before and after mixing
Unknown: no label or published stability study on file says how to store Growth hormone-releasing hormone, before or after mixing. The mixing guide sets out the general rules, with their sources: keep a mixed vial in the fridge, and use it promptly, as the bacteriostatic water label says of any drug dissolved in it. The 28 days often quoted is the limit for an opened multiple-dose vial from a manufacturer, an outer limit set for sterility, not a time a mixed solution has been shown to keep. Nobody has published how long Growth hormone-releasing hormone stays intact once mixed.
How it is taken
As it was given in human studies: Subcutaneous injection (Twice daily; Growth hormone deficiency, prepubertal (20 children)); Subcutaneous (Every 3 hours by infusion pump; Growth hormone deficiency, pulsatile pump (2 children)); Intravenous (Single bolus; Stimulation test, children (202 children)).
For injection technique, sites and needle disposal, see the mixing guide.
Source: Used in human trials: the route and frequency of each row in Dosing Data below.
What to expect, and when
How long it stays in the body: not established by a measurement cited on this entry.
How long the doses were given: Growth hormone deficiency, prepubertal (20 children): Up to 4 years; Growth hormone deficiency, pulsatile pump (2 children): 6 months; Stimulation test, children (202 children): Once.
When effects appear: unknown; no source on this page gives a time to effect for Growth hormone-releasing hormone. Results reported in the studies are under Published Research.
Source: Used in human trials, the duration of each row in Dosing Data below.
Side effects, and when to stop or get help
From the Side Effects section: No adverse effects noted in 20 children treated twice daily for up to four years; Reduced REM or deep sleep in young women given night-time pulses; Loss of response with continuous exposure (pituitary desensitisation). Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Growth hormone-releasing hormone. Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“From the abstracts of the studies above, which report little on safety”).
Interactions
Unknown: a PubMed search for human interaction studies of Growth hormone-releasing hormone (reviewed 2026-10-28) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Growth hormone-releasing hormone products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder; it checks the measured mass against Growth hormone-releasing hormone's expected mass, 5,039.7 Da, from this entry's molecular data. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: Research Chemical (Not an FDA-approved drug under this name). Sport: Prohibited at all times (S2.2.4).
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
From the abstracts of the studies above, which report little on safety.
Contraindications & Cautions
There is no label for GHRH(1-44).
Legal Status
GHRH(1-44) is not an approved drug; its analogues sermorelin and tesamorelin are covered on their own entries.
Frequently Asked Questions
?What is GHRH?
Growth hormone-releasing hormone, a 44-amino-acid peptide from the hypothalamus that makes the pituitary release growth hormone. It was first isolated in 1982 from a pancreatic tumour that caused acromegaly.
?How is GHRH different from sermorelin and tesamorelin?
Sermorelin is GHRH's first 29 amino acids and tesamorelin is a modified GHRH analogue. Each is a different molecule with its own entry and its own trials.
?Was GHRH ever used as a treatment?
In studies. Children with growth hormone deficiency grew faster on twice-daily injections or pump pulses, but it was never approved as a treatment.
?What is the GHRH plus arginine test?
A stimulation test for adult growth hormone deficiency, accepted as an alternative to the insulin tolerance test. Production of GHRH for the test was later stopped, which left a gap in diagnosis.
?Is GHRH banned in sport?
Yes. Growth hormone-releasing hormone is named on the World Anti-Doping Agency's prohibited list.
References
- [pubmed] Guillemin R, et al. "Growth hormone-releasing factor from a human pancreatic tumor that caused acromegaly." Science, 1982;218(4572):585-7. PMID: 6812220.
- [pubmed] Rivier J, et al. "Characterization of a growth hormone-releasing factor from a human pancreatic islet tumour." Nature, 1982;300(5889):276-8. PMID: 6292724.
- [review] Gabellieri E, et al. "Testing growth hormone deficiency in adults." Front Horm Res, 2010;38:139-144. PMID: 20616504.
- [pubmed] Thorner MO, et al. "Acceleration of growth in two children treated with human growth hormone-releasing factor." N Engl J Med, 1985;312(1):4-9. PMID: 3917299.
- [clinical-trial] Duck SC, et al. "Long-term treatment with GHRH [1-44] amide in prepubertal children with classical growth hormone deficiency." J Pediatr Endocrinol Metab, 1999;12(4):531-6. PMID: 10417969.
- [pubmed] Takano K, et al. "Plasma GH response to hpGRF-44 in normal children of short stature and patients with GH deficiency." Endocrinol Jpn, 1984;31(1):41-8. PMID: 6428864.
- [pubmed] Takano K, et al. "Plasma growth hormone (GH) responses to single and repetitive subcutaneous administration of GH releasing factor (hpGRF-44) in normal and GH deficient children." Acta Endocrinol (Copenh), 1985;108(1):11-9. PMID: 3918397.
- [pubmed] Takano K, et al. "Plasma growth hormone secretion during constant growth hormone-releasing factor infusion." Endocrinol Jpn, 1984;31(6):681-5. PMID: 6442696.
- [pubmed] Bozzola M, et al. "Synthetic growth hormone-releasing hormone (GHRH 1-44) in the differential diagnosis between hypothalamic and pituitary GH deficiency." J Endocrinol Invest, 1986;9(6):503-6. PMID: 3106460.
- [clinical-trial] Mathias S, et al. "Systemic growth hormone-releasing hormone (GHRH) impairs sleep in healthy young women." Psychoneuroendocrinology, 2007;32(8-10):1021-7. PMID: 17850984.
- [clinical-trial] Schüssler P, et al. "Growth hormone-releasing hormone and corticotropin-releasing hormone enhance non-rapid-eye-movement sleep after sleep deprivation." Am J Physiol Endocrinol Metab, 2006;291(3):E549-56. PMID: 16912060.
- [clinical-trial] Iovino M, et al. "Repetitive growth hormone-releasing hormone administration restores the attenuated growth hormone (GH) response to GH-releasing hormone testing in normal aging." J Clin Endocrinol Metab, 1989;69(4):910-3. PMID: 2506218.
- [pubmed] Iovino M, et al. "Difference in growth hormone response to growth hormone-releasing hormone (GHRH) testing following GHRH subacute treatment in normal aging and growth hormone-deficient adults: possible perspectives for therapeutic use of GHRH or its analogs in elderly subjects?." Immunopharmacol Immunotoxicol, 2011;33(2):334-7. PMID: 20843274.
- [review] Caputo M, et al. "The history of an effective, specific and sensitive diagnostic test: the GHRH test in clinical practice." Rev Endocr Metab Disord, 2025;26(3):353-369. PMID: 39681762.
- [review] Zendran I, et al. "Acromegaly Caused by Ectopic Growth Hormone Releasing Hormone Secretion: A Review." Front Endocrinol (Lausanne), 2022;13:867965. PMID: 35757397.
- [review] Borson-Chazot F, et al. "Acromegaly induced by ectopic secretion of GHRH: a review 30 years after GHRH discovery." Ann Endocrinol (Paris), 2012;73(6):497-502. PMID: 23122576.
- [pubmed] Frohman LA, et al. "Dipeptidylpeptidase IV and trypsin-like enzymatic degradation of human growth hormone-releasing hormone in plasma." J Clin Invest, 1989;83(5):1533-40. PMID: 2565342.
- [other] UniProt P01286 (SLIB_HUMAN), peptide residues 32-75 with C-terminal leucine amide, somatoliberin; read October 28, 2026. https://www.uniprot.org/uniprotkb/P01286/entry
- [other] PubChem CID 16132353, Somatorelin: formula C215H358N72O66S, molecular weight 5040. Read October 28, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/16132353
Sources & Citations
Studies were read from their PubMed abstracts on October 28, 2026; the sequence is from UniProt and the formula from PubChem. GHRH(1-44) has no label.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.