Sermorelin
The first 29 amino acids of GHRH: once an approved test and treatment for childhood growth hormone deficiency, discontinued, and now compounded for adults on thin evidence
Sermorelin is the shortest piece of growth hormone-releasing hormone that keeps the whole hormone's activity: its first 29 amino acids. FDA approved it as Geref in 1990 as a test of growth hormone reserve and in 1997 as a bedtime injection for children with idiopathic growth hormone deficiency. EMD Serono later discontinued Geref, and in 2013 FDA determined it had not been withdrawn for reasons of safety or effectiveness. Almost all of its evidence comes from children and diagnostic testing; adult use rests on commentary rather than trials.
What is it?
Sermorelin is growth hormone-releasing hormone cut down to its first 29 amino acids, with an amide at the end: GHRH(1–29)-NH2. A 1999 review describes it as the shortest synthetic peptide with the full biological activity of the natural hormone. Like the hypothalamic hormone it copies, it tells the anterior pituitary to release growth hormone; it does not supply growth hormone itself. CJC-1295 was built on this same 29-amino-acid sequence; tesamorelin instead modifies the full 44-amino-acid hormone.
It reached the market twice in the US under the name Geref. FDA approved a 0.05 mg ampoule on December 28, 1990 for testing the pituitary's growth hormone reserve, and 0.5 mg and 1.0 mg vials on September 26, 1997, which the 1999 review describes being used as a nightly injection for prepubertal children with idiopathic growth hormone deficiency. EMD Serono held both approvals and later stopped selling both products.
Its clinical evidence is almost entirely pediatric and diagnostic. In the 1999 review, an intravenous dose of 1 µg/kg was a rapid and relatively specific test for growth hormone deficiency, with fewer false positives than other provocative tests, but a normal response could not rule out deficiency caused by the hypothalamus. Once-daily injections of 30 µg/kg at bedtime raised height velocity in some prepubertal children over 12 months, with data from a few children suggesting the effect lasted 36 months. In short children who failed a first test, six days of priming injections separated pituitary from hypothalamic causes.
Adult use is a different matter. A 2006 commentary asked whether sermorelin was a better approach to adult-onset growth hormone insufficiency, and small studies from the 1980s and 1990s measured growth hormone responses in healthy adults, in acromegaly and after a nasal dose in children. None of the studies in our evidence set tested sermorelin for body composition, ageing or wellbeing in adults, which is how compounding pharmacies now sell it.
Because FDA determined on March 4, 2013 that Geref was not withdrawn for reasons of safety or effectiveness, generic versions could in principle be approved; none has been, as far as we could find. Sermorelin is not on FDA's 503A category lists; its status in sport is in the legal table below, from our regulatory tracker.
Mechanism of Action
Sermorelin acts where natural GHRH acts, on the growth hormone-releasing cells of the pituitary. The pathways below come from the pediatric review and from small human studies of the growth hormone response.
GHRH receptor: growth hormone
Given into a vein or under the skin, sermorelin specifically stimulates growth hormone secretion from the anterior pituitary. In healthy young adults an intravenous dose of 150 µg raised growth hormone to peaks 15 to 45 minutes later, and in short children a nasal dose produced a peak at 15 minutes that was still raised two hours later.
A test of the pituitary
Because it acts directly on the pituitary, the growth hormone response to 1 µg/kg separates a pituitary that can respond from one that cannot. A normal response does not exclude deficiency that starts in the hypothalamus, and six days of priming injections restored the response in half of a group of non-responding children, pointing to under-stimulated rather than failed pituitary cells.
Tumours that ignore the brain
In eight people with acromegaly, blocking muscarinic cholinergic signals did not change the growth hormone response to sermorelin, unlike in healthy people. The authors read this as a sign that growth hormone-secreting pituitary tumours are cut off from hypothalamic control.
Timing, and its successors
In the small human studies, growth hormone peaked 15 to 45 minutes after a dose. Later analogues were built to act for longer: tesamorelin adds a stabilising group to the full 44-amino-acid hormone, and CJC-1295 adds a group that binds albumin. In rat studies, sermorelin also stuck to plasma proteins such as albumin, which slowed its release from an implant.
Published Research
Our evidence set returned papers on sermorelin under several names, and 12 name it in their titles. The six cards below are four small human studies, the 1999 review of its pediatric use and one rat formulation study. A 2006 commentary on adult use has no abstract and appears in References without a card. Studies of [Nle27]-GHRH(1–29)-NH2, a norleucine analogue whose title the name-matching also accepts, are not carded, because it is a different molecule.
Diagnosis and treatment in children
A review of sermorelin in children with idiopathic growth hormone deficiency describes intravenous 1 µg/kg as a rapid and relatively specific diagnostic test, with fewer false positives than other provocative tests, although a normal response cannot exclude hypothalamic deficiency. Limited data showed that nightly subcutaneous injections of 30 µg/kg raised height velocity in some prepubertal children over 12 months, maintained to 36 months in a few.
Priming to find the cause
Sixteen short children who had not responded to a first GHRH test received GHRH(1–29)-NH2, 5 µg/kg under the skin, for six days. In eight, the growth hormone response to a repeat test rose from 6.0 to 18.0 ng/mL; in the other eight, priming did not raise it. The test separated children whose pituitary cells were under-stimulated from those with a pituitary deficiency.
Memory after one dose
Seventeen healthy young adults received 150 µg of GRF(1–29)-NH2 into a vein and six received placebo. Two hours later the treated group recalled more words from a list than the placebo group (14.8 vs 11.8), and growth hormone peaked 15 to 45 minutes after the injection. The study was small, and the groups were not randomly compared on the same test day.
A nasal dose in children
Five healthy prepubertal children with short stature received 100 µg/kg of GRF 1–29-NH2 as a nasal spray. Growth hormone rose promptly in all five, peaking at 15 minutes at 28.3 ng/mL on average, and was still raised at 120 minutes. One child had a burning nose; there were no other side effects.
Acromegaly and cholinergic blockade
Eight people with acromegaly had two GRF 1–29 tests (1 µg/kg into a vein), with and without the muscarinic blocker pirenzepine. Unlike in healthy people, the blocker did not change the growth hormone response, which the authors interpret as growth hormone-secreting tumours being disconnected from hypothalamic control.
Why it clumps in plasma
In laboratory tests GRF(1–29)-NH2 precipitated in salt solutions and in plasma, where it formed complexes with proteins such as albumin, transferrin, haptoglobin and immunoglobulin G. Loaded into biodegradable pellets implanted under the skin of rats, it was released slowly despite this complexation, but only a very small part of the dose was released.
Dosing Data
Sermorelin's only labelled doses belonged to Geref, which is no longer sold. The 1999 review describes 1 µg/kg intravenously as a diagnostic test and 30 µg/kg under the skin once nightly for treating children; the adult doses in circulation today come from compounding practice, not trials.
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.
→ Full Sermorelin dosage guide — the Geref-era doses for children, the adult figures used in compounding, and what separates the two.
Side Effects & Contraindications
Reported Side Effects
The studies in our evidence set were single doses or short courses and reported few side effects. The Geref labels, which listed its adverse reactions, were withdrawn with the product and are not re-read here.
Contraindications & Cautions
No current label defines who should avoid sermorelin. These cautions follow from how it works.
Legal Status
Sermorelin was approved in the US as Geref and is no longer sold as an approved product. Status as of September 26, 2026.
Frequently Asked Questions
?Was sermorelin FDA-approved?
Yes, as Geref. FDA approved a diagnostic ampoule on December 28, 1990 and treatment vials on September 26, 1997, both held by EMD Serono. The products were later discontinued, and in 2013 FDA determined that Geref had not been withdrawn from sale for reasons of safety or effectiveness.
?Is sermorelin the same as tesamorelin or CJC-1295?
No. Sermorelin is GHRH's first 29 amino acids. Tesamorelin is the full 44-amino-acid hormone with a stabilising group, approved for abdominal fat in HIV. CJC-1295 is a modified version of the 29-amino-acid sequence with a group that binds albumin so it lasts about a week. All three act on the same pituitary receptor.
?Does sermorelin work in adults?
No trial in our evidence set tested it in adults for body composition, ageing or wellbeing. Its measured effects in adults are growth hormone responses to single doses, and its treatment data come from children with growth hormone deficiency. A 2006 commentary raised adult-onset insufficiency as a possible use; that is a question, not evidence.
?How was sermorelin used in children?
As a nightly injection under the skin, 30 µg/kg at bedtime, for prepubertal children with idiopathic growth hormone deficiency. A 1999 review reports that height velocity rose significantly over 12 months in some children, with data from a few suggesting the gain held to 36 months. It was also used as a 1 µg/kg intravenous test of pituitary growth hormone reserve.
?Why do compounding pharmacies sell sermorelin?
Its approved product was discontinued rather than withdrawn for safety, and FDA's 2013 determination confirmed that. Whether a particular compounded product is lawful depends on the rules for the pharmacy that makes it, which this page does not assess; compounded sermorelin is not an FDA-approved drug either way.
?Is sermorelin banned in sport?
The legal table on this page reports its status under the WADA Prohibited List from our regulatory tracker, which checks it against the current List.
References
- [fda-pi] Geref (sermorelin acetate) Prescribing Information. EMD Serono. (Discontinued.)
- [other] Food and Drug Administration. Determination that GEREF (sermorelin acetate) injection was not withdrawn from sale for reasons of safety or effectiveness. Federal Register 78:14096, March 4, 2013 (Docket FDA-2012-P-1071).
- [review] Prakash A, et al. "Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency." BioDrugs, 1999;12(2):139-57. PMID: 18031173.
- [pubmed] Bueno G, et al. "Priming with GHRH (1-29) NH2: an aid in differential diagnosis between hypothalamic and pituitary deficiencies." J Pediatr Endocrinol, 1994;7(4):309-16. PMID: 7735368.
- [pubmed] Alvarez XA, et al. "Effects of GRF (1-29) NH2 on short-term memory: neuroendocrine and neuropsychological assessment in healthy young subjects." Methods Find Exp Clin Pharmacol, 1990;12(7):493-9. PMID: 2087150.
- [pubmed] Borkenstein M. "The effects of intranasal insufflation of growth hormone releasing factor analogue GRF 1-29 NH2 on growth hormone secretion in children with short stature." Acta Endocrinol Suppl (Copenh), 1986;279:135-8. PMID: 2877535.
- [pubmed] Jordan V, et al. "Lack of effect of muscarinic cholinergic blockade on the GH responses to GRF 1-29 and TRH in acromegalic subjects." Clin Endocrinol (Oxf), 1986;24(4):415-20. PMID: 2874906.
- [pubmed] Mariette B, et al. "Interactions of GRF(1-29)NH2 with plasma proteins and their effects on the release of the peptide from a PLAGA matrix." J Control Release, 2005;106(3):253-62. PMID: 15987661.
- [review] Walker RF. "Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?." Clin Interv Aging, 2006;1(4):307-8. PMID: 18046908.
Sources & Citations
Every citation on this page is PubMed-indexed and has been checked against its record, except the Geref prescribing information and FDA's 2013 Federal Register determination, which are cited as published. A 2006 commentary appears in References without a card because it has no abstract. Grey Peptides sells nothing and links to no vendor.
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.