Sermorelin
Also known as: GHRH(1-29) · growth hormone releasing hormone 1-29 · Geref · Sermorelin acetate
The 1-29 amino acid fragment of endogenous growth hormone-releasing hormone (GHRH), historically licensed for paediatric growth hormone deficiency diagnostics and long the reference GHRH research analogue prior to CJC-1295's dominance.
Sermorelin is the GHRH(1-29) fragment historically licensed for paediatric growth-hormone diagnostics; shorter-acting GHRH-arm alternative to CJC-1295.
Evidence tier: A — ≥1 RCT + meta-analysis or approved clinical use
- Category
- Sleep & Recovery
- Half-life
- Approximately 12 minutes plasma
Section 1
Overview
Sermorelin is the 1-29 amino acid fragment of endogenous growth hormone-releasing hormone (GHRH) — the shortest fragment that retains full GH-releasing activity of the parent 44-amino-acid GHRH. It was developed and licensed as Geref by EMD Serono for paediatric growth hormone deficiency diagnostics and treatment, providing the reference GHRH analogue for GH-axis research prior to the widespread adoption of the DAC-modified CJC-1295 in more recent research practice.
The compound's licensed clinical use has diminished with the availability of DAC-modified GHRH analogues (like CJC-1295) that offer substantially longer plasma half-life and the availability of recombinant human GH itself. Sermorelin nonetheless retains research-community relevance as the shorter-acting GHRH-arm option for research applications where the DAC-modified analogue's extended action is not desired.
The cognitive-relevance angle is indirect, following the same GH-axis sleep-cognition framework as CJC-1295 and Ipamorelin — sleep-onset GH pulse augmentation and downstream IGF-1 effects on CNS-relevant signalling. The compound's licensed clinical history provides a substantial acute-safety database, but no direct cognitive-endpoint clinical trials have been completed.
Section 2
Discovery & History
- Developed as the 1-29 amino acid fragment of endogenous GHRH, retaining full GH-releasing activity of the parent 44-amino-acid molecule.
- Licensed as Geref by EMD Serono for paediatric growth hormone deficiency diagnostics and treatment, providing the licensed-clinical-use safety database.
- Widely used in the 1990s and 2000s as the reference GHRH analogue for GH-axis research prior to the widespread adoption of DAC-modified analogues.
- Licensed clinical use has diminished with the availability of DAC-modified GHRH analogues and recombinant human GH; commercial availability varies across jurisdictions.
- Continues to be used in research contexts as the shorter-acting GHRH-arm option.
Section 3
Mechanism of Action
- 1Direct agonism at the GHRH receptor on pituitary somatotroph cells, driving GH release from the pituitary in the physiological pulsatile pattern.
- 2Preservation of the endogenous GHRH pulsatility rather than continuous supraphysiological receptor stimulation — the mechanism-of-action framework for the physiological-GH-restoration research applications.
- 3Combined pulse-effect with GH-releasing peptides — Sermorelin provides the GHRH-arm signalling that potentiates the ghrelin-receptor arm signalling from Ipamorelin or similar compounds.
- 4Systemic GH-mediated effects — increased IGF-1 production by hepatocytes, downstream metabolic and tissue-repair effects, and CNS-relevant IGF-1 signalling.
- 5Sleep-onset GH pulse augmentation — the endogenous slow-wave-sleep-associated GH pulse mechanism relevant to the indirect cognitive-relevance research angle.
- 6Short plasma half-life (~12 minutes) reflecting the peptide's susceptibility to DPP-4 cleavage — the property that motivated the subsequent development of DAC-modified analogues like CJC-1295.
- 7Reported effects on body composition (lean mass, adiposity) via the systemic GH mechanism.
Section 4
Researched Benefits
Findings reported in the published preclinical and clinical literature. Effects in research contexts do not constitute claims of therapeutic benefit in humans.
- 1Licensed clinical use history providing substantial acute-safety database — an unusual advantage for a GHRH-family compound.
- 2Reference GHRH-fragment analogue with well-characterised pharmacology.
- 3Effective research-tool combination with GH-releasing peptides for physiological GH-pulse research.
- 4Shorter-acting profile than DAC-modified CJC-1295 — appropriate for research applications where the extended-acting profile is not desired.
- 5Reported effects on body composition, tissue-repair markers, and metabolic parameters in research applications.
- 6Preservation of physiological GH-pulse pattern rather than continuous supraphysiological GH exposure.
- 7Sleep-onset GH pulse augmentation with indirect cognitive-relevance via sleep-mediated memory consolidation.
Section 5
Theoretical Dosing & Protocols
| Route | Dosage | Frequency | Duration | Source |
|---|---|---|---|---|
| Subcutaneous injection (clinical trial in growth hormone-deficient children) | 30 micrograms per kg per day of GHRH-(1-29), given at bedtime, dose used in Thorner et al., 1996 (PMID 8772599; Geref International Study Group) | Once daily at bedtime | Up to 1 year | Thorner et al., 1996 (PubMed 8772599) |
Note: Geref (sermorelin acetate, NDA 020443) is listed as discontinued on Drugs@FDA, which states that its label is not available there, so no label dose is given. Sermorelin is the 29-amino-acid GHRH analogue GHRH-(1-29), and a published review of its use in children reports the same once-daily bedtime subcutaneous dose (Prakash and Goa, 1999, PMID 18031173). The dose shown is from a paediatric trial, not a recommendation.
Section 6
Administration Routes
- Subcutaneous injection — the primary route in research and historical licensed clinical use.
- Intravenous administration used in some diagnostic-testing contexts historically.
- Intramuscular administration in some research contexts.
- Oral administration is not viable — the peptide is degraded by gastrointestinal proteases.
Section 7
Safety Profile
Commonly reported
- · Well-tolerated in the historical licensed clinical use with substantial safety database.
- · Injection-site reactions with subcutaneous administration.
- · Occasional headache during initial dosing.
- · Mild transient effects on blood pressure and heart rate.
- · Fluid retention and mild peripheral oedema — expected GH-mediated effect.
Rare / theoretical
- · Diabetes precipitation or worsening of glycaemic control in susceptible research subjects.
- · GH-mediated effects on cardiac hypertrophy in chronic high-dose research.
- · Theoretical GH-mediated tumour-growth concerns in active malignancy.
- · Rare hypersensitivity reactions.
- · Development of anti-drug antibodies during chronic dosing.
Contraindications
- · No entry for Sermorelin was found in the electronic medicines compendium (emc) on 17 October 2026.
- · Active malignancy — theoretical contraindication via the GH-axis mechanism.
- · Pregnancy and lactation.
- · Severe uncontrolled diabetes.
Section 8
UK & EU Regulatory Context
United Kingdom
No entry for Sermorelin was found in the electronic medicines compendium (emc) on 17 October 2026.
European Union
Not on the EMA's list of centrally authorised medicines (checked 17 October 2026). Drugs@FDA lists Geref (sermorelin, EMD Serono, NDA 019863 and NDA 020443) as discontinued.
Section 9
Clinical Studies Summary
Sermorelin in paediatric growth hormone deficiency
The historical licensed-clinical-use evidence base in paediatric growth hormone deficiency indications, providing the substantial acute-safety database from decades of clinical use and the mechanistic-clinical framework for the GHRH-analogue research applications.
Sermorelin + GH-releasing peptide combined GH-release research
Research characterising the combined-arm effect of Sermorelin plus GH-releasing peptides on GH pulse magnitude, providing the reference GHRH-arm characterisation for the modern GH-axis stack research practice.
Sermorelin pharmacokinetics and GH pulse profile
Clinical pharmacology characterisation of Sermorelin's pharmacokinetic profile and GH-releasing effect time-course, demonstrating the short plasma half-life (~12 minutes) and the acute GH-pulse response that motivated the subsequent development of DAC-modified analogues.
Section 10
Frequently Asked Questions
Section 10a
Practical Research Guidance
Cycle guidance
Reconstitution & storage
UK sourcing notes
Section 11
Sourcing for Laboratory Research
Sourcing Sermorelin for laboratory research
Researchers in the United Kingdom and elsewhere typically obtain Sermorelin from specialist research-chemical suppliers. Purity, third-party testing, and supplier transparency are the principal differentiators worth evaluating before placing an order. The two suppliers below are commonly referenced in UK research contexts.
Reminder: this page is educational. Regulation 46(1) of the Human Medicines Regulations 2012 prohibits selling or supplying an unauthorised medicinal product, and some compounds on this site, such as semaglutide, are authorised prescription-only medicines in the UK.