Page data last changed: . Chemistry registry snapshot: . Registry refreshes and identity assessments are separate from scientific content review.
The first 29 residues of human GHRH, amidated — a former paediatric medicine that became one of the most-searched grey-market peptides.
Also known as: GHRH(1-29) · GRF(1-29)-NH2 · Geref · sermorelin acetate
Part of the Growth hormone & IGF peptides cluster
Overview
Sermorelin is a synthetic 29-amino-acid peptide (C149H246N44O42S, ≈3,358 Da) that reproduces the amino-terminal, biologically active segment of human growth hormone-releasing hormone, GHRH(1-29)-NH2. It activates the GHRH receptor on pituitary somatotrophs to release growth hormone. It was approved as Geref for diagnosing and treating growth hormone deficiency in children, but US marketing was discontinued in 2008; it has no current approval in the US and is prohibited in sport.
Source & context
Biological / chemical source: Synthetic GHRH (1-29) amide
Primary research or clinical context: Formerly approved (Geref) for diagnosis and treatment of growth hormone deficiency in children; US marketing discontinued in 2008. Sold unapproved as a research peptide.
What sermorelin is
Sermorelin is the shortest fragment of human growth hormone-releasing hormone that retains full activity: the first 29 of GHRH's 44 amino acids, with a C-terminal amide. The IUPHAR/BPS Guide to Pharmacology describes it as a synthetically produced 29-amino-acid peptide, GRF(1-29)-NH2, representing the amino-terminal segment of endogenous GHRH; the approved drug was the acetate salt. Its molecular formula is C149H246N44O42S and its average mass about 3,358 Da. Because it is the native sequence rather than an engineered analogue, it is the reference point against which CJC-1295 and tesamorelin — both GHRH(1-29)-based designs — are understood.
Sequence and structure
In one-letter code: Y-A-D-A-I-F-T-N-S-Y-R-K-V-L-G-Q-L-S-A-R-K-L-L-Q-D-I-M-S-R-NH2. There are no non-canonical residues and no lipid: sermorelin is simply GHRH truncated after arginine 29 and amidated. The N-terminal tyrosine and alanine are the region that GHRH-cleaving enzymes attack, which is why the engineered analogues on this site alter position 2 (CJC-1295 and tesamorelin) — sermorelin itself does not. Doping-control chemists have synthesised fragments of the sequence (residues 1–11, 13–20 and 22–29) as reference standards for detecting its metabolites in urine (González-López et al., Biomedical Chromatography 2023).
Mechanism
Sermorelin mimics endogenous GHRH: it binds and activates the growth hormone-releasing hormone receptor on the pituitary, triggering release of growth hormone, which in turn raises insulin-like growth factor 1. Unlike the ghrelin-receptor peptides (ipamorelin, GHRP-2, GHRP-6) it acts at the GHRH receptor, so it stimulates the physiological pulsatile pathway rather than the ghrelin pathway; the two receptor classes are complementary, which is why they are so often discussed together. The response depends on an intact pituitary: sermorelin can only amplify what the gland can produce.
What the clinical literature shows
The evidence is paediatric and historical. A 1999 review (Prakash & Goa, BioDrugs) concluded that sermorelin is a well-tolerated GHRH analogue suitable as a provocative test of growth hormone deficiency when given as a single intravenous 1 µg/kg dose alongside conventional tests, and that limited data suggested once-daily subcutaneous 30 µg/kg promoted growth in some prepubertal children with idiopathic growth hormone deficiency. That was the basis of the Geref approval. A 2006 editorial (Walker, Clinical Interventions in Aging) proposed sermorelin as an approach to adult-onset growth hormone insufficiency, but the pack contains no controlled adult trial supporting that proposal.
Regulatory status
The IUPHAR record flags sermorelin as approved and withdrawn: it was used to treat growth hormone deficiency or growth failure in children, and marketing approval has been discontinued in the US, while individual national agencies may continue to grant authorisation. As of September 2026 there is no approved sermorelin product in the US. Its administration is prohibited by the World Anti-Doping Agency, and anti-doping laboratories have developed specific urine assays for it (Coppieters et al., Journal of Pharmaceutical and Biomedical Analysis 2022; Cristea et al., Analytical Biochemistry 2023).
| Sermorelin | CJC-1295 (with DAC) | Tesamorelin | |
|---|---|---|---|
| Basis | Native GHRH(1-29)-NH2 | GHRH(1-29) with substitutions + albumin-binding linker | GHRH(1-44) with a stabilising N-terminal modification |
| Length | 29 aa | 30 aa | 44 aa |
| Half-life | Not stated in the pack (short; native sequence) | 5.8–8.1 days (Teichman et al., 2006) | Not stated in the pack |
| Status (Sept 2026) | Formerly approved; US marketing discontinued 2008 | Never approved; phase 2 terminated | Approved (Egrifta, 2010, HIV lipodystrophy) |
Sermorelin in the grey market and in sport
Sermorelin is among the most-searched peptides on the web, and recent reviews describe it as one of the GHRH analogues encountered in recreational and professional sport, bodybuilding and online self-administration protocols (Coutinho et al., Journal of Sports Medicine and Physical Fitness 2026; Dominikowski et al., Frontiers in Endocrinology 2026). WADA prohibits GHRH and its synthetic analogues, and although admissions and intelligence indicate use, they were historically rarely found in anti-doping samples because of low urinary concentrations and limited metabolism data — a gap the detection literature has been closing (Memdouh et al., Drug Testing and Analysis 2021). Vials sold as “research sermorelin” are outside any approval and of unverified content.
How it compares with the other secretagogues
CJC-1295 keeps sermorelin's 29-residue frame but swaps four residues and adds a reactive linker so the peptide binds serum albumin, stretching its action from hours to a week. Tesamorelin keeps the full 44-residue hormone with a stabilising N-terminal group and is the only GHRH analogue currently approved. Ipamorelin and the GHRPs act at a different receptor (the ghrelin receptor) and are often discussed as a pairing with GHRH analogues; MK-677 (ibutamoren) does the same job orally as a non-peptide. Sermorelin's distinction is that it is the unmodified native fragment — the cleanest pharmacology and the shortest action.
What is not known
The pack contains no randomised trial of sermorelin in adults for body composition, ageing or performance, no modern pharmacokinetic study, and no systematic safety data outside the paediatric programme. The 2026 sports-medicine reviews in the pack characterise the growth-hormone secretagogues collectively as having promising but limited evidence and note that patients often perceive them as low-risk despite the absence of efficacy or safety data (Tewari et al., American Journal of Sports Medicine 2026). This profile is educational; it is not guidance on obtaining or using any product and it is not medical advice.
Sequence
One-letter sequence commonly cited for Sermorelin (educational; isoforms and modifications may differ):
YADAIFTNSYRKVLGQLSARKLLQDIMSR
Residues plotted ~100° apart around an α-helix — clustering of one color reveals an amphipathic face.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.
- Molecular form
- Residues 1–29 of human GHRH (the full hormone is 44 residues); the approved product was the acetate salt of the C-terminally amidated peptide
- Species
- Not established by this molecular identity audit
- Termini (N / C)
- Not specified / Amide (Arg29-NH2)
Average reference mass
Reference policy updated: 2026-10-05
- IUPHAR/BPS source snapshot · 2026-10-01
- PubChem molecular record · 2026-10-01
- Molecular formula
- C149H246N44O42S
- Average reference mass
- ≈ 3,357.9
- Receptors
- Growth hormone-releasing hormone receptor (GHRH-R), a class B G-protein-coupled receptor on pituitary somatotrophs
- Backbone
- Residues 1–29 of human GHRH (the full hormone is 44 residues); the approved product was the acetate salt of the C-terminally amidated peptide
- C-terminus
- Amide (Arg29-NH2)
- Status
- Formerly approved (Geref, US); marketing discontinued 2008. National authorisations may persist elsewhere per IUPHAR. WADA-prohibited.
- PubChem CID: 16132413
- IUPHAR ligand: 6998
- DrugBank: DB00010
- CAS RN: 86168-78-7
- UNII: 89243S03TE
Chemistry values: curated profile, PubChem, IUPHAR/BPS Guide to Pharmacology · fetched 2026-10-01.
Clinical development snapshot
ClinicalTrials.gov lists 27 registered studies with “Sermorelin” as an intervention (snapshot 2026-09-06). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT06554717 | Tesamorelin as an Adjunct to Exercise for Improving Physical Function in HIV | Phase 2 | recruiting | 2026-05-19 |
| NCT03375788 | Growth Hormone Releasing Hormone Analog to Improve Nonalcoholic Fatty Liver Disease and Associated Cardiovascu | Phase 2 | completed | 2025-11-20 |
| NCT00720902 | Adult Growth Hormone Deficiency and Cardiovascular Risk | Phase 4 | terminated | 2022-11-16 |
| NCT00608023 | TH9507 Extension Study in Patients With HIV-Associated Lipodystrophy | Phase 3 | completed | 2022-09-30 |
| NCT02196831 | Tesamorelin Effects on Liver Fat and Histology in HIV | Not applicable | completed | 2020-01-27 |
| NCT02553603 | The Effect of Growth Hormone Releasing Hormone on Cognitive Function in Individuals With Mild Cognitive Impair | Phase 1 | completed | 2019-11-04 |
Sermorelin — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Residues 1–29 of human GHRH (the full hormone is 44 residues); the approved product was the acetate salt of the C-terminally amidated peptideAverage reference mass: 3,357.9 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- EditorialProfile content reviewed and updated by the editorial team.
FAQ about Sermorelin
What is Sermorelin?+
Sermorelin is a synthetic 29-amino-acid peptide (C149H246N44O42S, ≈3,358 Da) that reproduces the amino-terminal, biologically active segment of human growth hormone-releasing hormone, GHRH(1-29)-NH2. It activates the GHRH receptor on pituitary somatotrophs to release growth hormone. It was approved as Geref for diagnosing and treating growth hormone deficiency in children, but US marketing was discontinued in 2008; it has no current approval in the US and is prohibited in sport.
What Canadian product status is recorded for Sermorelin?+
Canadian product status for Sermorelin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the typical length of Sermorelin?+
Sermorelin is commonly described as approximately 29 amino acids (GHRH analogue (former prescription medicine)).
What is sermorelin?+
A synthetic 29-amino-acid peptide equal to the active N-terminal fragment of human GHRH (GRF 1-29, amidated). It activates the GHRH receptor to release growth hormone.
Is sermorelin approved?+
It was — as Geref, for growth hormone deficiency in children — but US marketing was discontinued in 2008. As of September 2026 there is no approved US product; IUPHAR notes national approvals may persist elsewhere.
What is sermorelin's half-life?+
The evidence pack does not give a figure. As an unmodified native sequence it is short-acting, which is precisely what CJC-1295 (5.8–8.1 days) and tesamorelin were engineered to change.
Sermorelin vs CJC-1295 — what is the difference?+
CJC-1295 is sermorelin's 29-residue frame with four substitutions and an albumin-binding linker that extends its action to about a week. Neither is currently approved.
Sermorelin vs ipamorelin?+
Different receptors: sermorelin acts at the GHRH receptor, ipamorelin at the ghrelin receptor. Both stimulate growth hormone release; neither is approved.
Is sermorelin banned in sport?+
Yes. GHRH and its synthetic analogues are prohibited by WADA, and specific urine detection methods exist.
What are sermorelin's side effects?+
The paediatric literature describes it as well tolerated. The pack contains no systematic adult safety data; grey-market products add the unknowns of unverified content.
Further reading
- Hormone axisGH Secretagogue Peptides Explained: CJC-1295, Ipamorelin, GHRPsEducational overview of growth hormone secretagogue peptides—GHRH analogs vs GHRPs, DAC vs no DAC, receptors, and research context.
- ComparisonCJC-1295 vs Sermorelin: Comparing GHRH AnalogsAn educational comparison of CJC-1295 and sermorelin—two GHRH-analog research compounds—covering DAC vs no-DAC design, half-life concepts, and framing. Not medical advice.
- GH secretagoguesTesamorelin vs CJC-1295: Two GHRH Analogs, ComparedTesamorelin and CJC-1295 are both GHRH analogs, but one is an approved medicine and the other a research compound. Compare their design, half-life, and how the literature treats them. Educational only.
- Not a peptideIs MK-677 (Ibutamoren) a Peptide? No — It Is an Oral Small-Molecule Ghrelin Mimetic. What the Trials ShowedMK-677 (ibutamoren) is sold next to peptides and stacked with them, but it is a small synthetic molecule that activates the ghrelin receptor by mouth. This guide explains what it is, how it differs from GHRH and GHRP peptides, what its clinical trials showed — including the safety signal that stopped one — and its regulatory status.
- CanadaAre Peptides Legal in Canada? A Regulatory GuideAn educational overview of how Health Canada regulates peptides—drug authorization, DINs, the “research use only” gray area, and import ambiguity. Not legal advice.
- FoundationsWhat Are Research Peptides? A Clear Educational GuideLearn what “research peptides” means, how they differ from approved peptide drugs, quality markers (COA, purity), and how to study them responsibly.
Related peptides
References & further reading
- 1.Prakash et al. (1999). Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs
- 2.Chen et al. (1993). A comparative study of growth hormone (GH) and GH-releasing hormone(1-29)-NH2 for stimulation of growth in children with GH deficiency. Acta Paediatr Suppl
- 3.Thorner et al. (1996). Once daily subcutaneous growth hormone-releasing hormone therapy accelerates growth in growth hormone-deficient children during the first year of therapy. Geref International Study Group. J Clin Endocrinol Metab
- 4.Kirk et al. (1994). Treatment with GHRH(1-29)NH2 in children with idiopathic short stature induces a sustained increase in growth velocity. Clin Endocrinol (Oxf)
- 5.Neyzi et al. (1993). Growth response to growth hormone-releasing hormone(1-29)-NH2 compared with growth hormone. Acta Paediatr Suppl
- 6.Arrigo et al. (1992). Diagnostic value of growth hormone-releasing hormone test in children and adolescents with idiopathic growth hormone deficiency. Eur J Pediatr
- 7.Ranke et al. (1986). Testing with growth hormone-releasing factor (GRF(1-29)NH2) and somatomedin C measurements for the evaluation of growth hormone deficiency. Eur J Pediatr
- 8.Albini et al. (1988). Diagnostic value of the growth hormone-releasing factor stimulation test. Clin Pharmacol Ther
- 9.Losa et al. (1984). Stimulation of growth hormone secretion with human growth hormone releasing factors (GRF1-44, GRF1-40, GRF1-29) in normal subjects. Klin Wochenschr
- 10.Vittone et al. (1997). Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men. Metabolism
- 11.Khorram et al. (1997). Endocrine and metabolic effects of long-term administration of [Nle27]growth hormone-releasing hormone-(1-29)-NH2 in age-advanced men and women. J Clin Endocrinol Metab
- 12.Baker et al. (2012). Effects of growth hormone–releasing hormone on cognitive function in adults with mild cognitive impairment and healthy older adults: results of a controlled trial. Arch Neurol
- 13.Friedman et al. (2013). Growth hormone-releasing hormone effects on brain γ-aminobutyric acid levels in mild cognitive impairment and healthy aging. JAMA Neurol
- 14.Walker (2006). Sermorelin: a better approach to management of adult-onset growth hormone insufficiency?. Clin Interv Aging
- 15.Memdouh S et al. (2021). Advances in the detection of growth hormone releasing hormone synthetic analogs. Drug Testing and Analysis
- 16.Coppieters G et al. (2022). An antibody-free, ultrafiltration-based assay for the detection of growth hormone-releasing hormones in urine. Journal of Pharmaceutical and Biomedical Analysis
- 17.González-López NM et al. (2023). In-house standards derived from doping peptides: enzymatic and serum stability of GHRP and GHRH-related peptides. Biomedical Chromatography
- 18.Coutinho LFD et al. (2026). A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding. Journal of Sports Medicine and Physical Fitness
- 19.Dominikowski A et al. (2026). The emerging landscape of performance-enhancing peptides modulating the GH-IGF1 axis. Frontiers in Endocrinology
- 20.PubChem — Sermorelin (CID 16129620)