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 |
|---|---|---|---|
| Subcutaneous injection (research and historical licensed use) | Historical licensed dosing was 200-500 mcg subcutaneously; research protocols use 100-300 mcg per dose | 1-2× daily in most research configurations; once-daily in the historical licensed indication | Historical chronic clinical use extended for months to years in paediatric indications |
Note: The historical licensed dosing provides the reference for research-context dose selection.
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
- · Not currently authorised for human use in the UK.
- · Active malignancy — theoretical contraindication via the GH-axis mechanism.
- · Pregnancy and lactation.
- · Severe uncontrolled diabetes.
Section 8
UK & EU Regulatory Context
United Kingdom
Not currently a licensed medicine in the UK.
European Union
Not currently approved by the EMA. Historically licensed as Geref for diagnostic and paediatric growth-deficiency indications; marketing status has changed across jurisdictions.
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: research peptides are sold strictly for in vitro and preclinical laboratory purposes. Importation or supply for human consumption is not permitted under UK medicines legislation.