Sermorelin
Also known as: Geref · GRF 1-29 · Sermorelin acetate
Contents
MW
3357.93 Da
Amino Acids
29 AA
Half-Life
10-20 minutes
Route
SubQ
CAS
86168-78-7
Formula
C149H246N44O42S
Amino Acid Sequence
YADAIFTNSYRKVLGQLSARKLLQDIMSR-NH2
Mechanism of Action
Sermorelin (GHRH 1-29) is a synthetic 29-amino acid peptide corresponding to the first 29 amino acids of endogenous GHRH — the biologically active portion. It was the FIRST FDA-approved GH secretagogue (as Geref Diagnostic and Geref for pediatric GH deficiency).
MECHANISM: Binds GHRH receptor (GHRHR) on pituitary somatotrophs → adenylyl cyclase → cAMP → PKA → GH gene transcription and release. Identical receptor and pathway to CJC-1295.
CRITICAL DIFFERENCE FROM CJC-1295: Sermorelin has NO DPP-IV resistance modifications. It is susceptible to rapid enzymatic degradation with a half-life of only 10–20 minutes (vs 30 min for CJC-1295 no-DAC). This produces very short, sharp GH pulses.
HISTORICAL SIGNIFICANCE: Sermorelin was FDA-approved for diagnostic testing of GH axis function and for treatment of pediatric GH deficiency. It was voluntarily withdrawn from market for business/commercial reasons (NOT safety concerns).
Now largely superseded by CJC-1295 (longer half-life, more practical dosing) but still widely available from compounding pharmacies and commonly used in anti-aging protocols.
Dosing Protocol
Low Dose
███ – ███ mcg/day
Standard Dose
███ mcg/day
High Dose
███ – ███ mcg/day
Dosing protocols are for paid members
Get exact dosing ranges, injection frequency, timing rationale, and reconstitution math.
Get Clinical Access — $79/moFrequency
Once nightly pre-sleep.
Half-Life
10-20 minutes
Reconstitution Guide
Full reconstitution protocol with BAC water volumes, concentration math, and units-to-draw per dose is available on the Clinical plan.
Unlock reconstitution guide →Clinical Warnings
Short half-life limits effectiveness vs CJC-1295.
Market withdrawal (business, not safety).
Still available compounded.
Same GH secretagogue warnings apply.
WADA prohibited.
Contraindications
Absolute
Active cancer
Pregnancy
Active pituitary tumor
Relative Cautions
Diabetes
History of cancer
Obesity
Side Effect Profile
Mild
- ●Flushing
- ●Injection site reaction
- ●Mild dizziness
Moderate
- ●Headache
- ●Nausea
- ●Drowsiness
Severe (Rare)
- ●Potential tumor growth acceleration
Synergistic Peptides
Common Stacks
Ipamorelin
GHRP-2
GHRP-6
Research Status
HISTORICAL FDA APPROVAL. PMID 1548339 (Corpas 1992): Improved GH/IGF-1 and body composition in elderly. PMID 15001742 (Walker 2004): GH deficiency adults body composition. Was FDA-approved (Geref). Withdrawn for commercial reasons.
Frequently Asked Questions
How does Sermorelin work?
Sermorelin (GHRH 1-29) is a synthetic 29-amino acid peptide corresponding to the first 29 amino acids of endogenous GHRH — the biologically active portion. It was the FIRST FDA-approved GH secretagogue (as Geref Diagnostic and Geref for pediatric GH deficiency). MECHANISM: Binds GHRH receptor (GHRHR) on pituitary somatotrophs → adenylyl cyclase → cAMP → PKA → GH gene transcription and release. Identical receptor and pathway to CJC-1295. CRITICAL DIFFERENCE FROM CJC-1295: Sermorelin has NO DPP-
What is the standard dose of Sermorelin?
Sermorelin dosing protocols are available with a ClinPep Clinical subscription. Dosing varies by indication and patient factors — consult a licensed healthcare provider. General frequency: Once nightly pre-sleep.
What is the half-life of Sermorelin?
The half-life of Sermorelin is 10-20 minutes. This determines optimal dosing frequency and timing.
Who should not use Sermorelin?
Sermorelin is absolutely contraindicated in: Active cancer; Pregnancy; Active pituitary tumor. Use with caution in: Diabetes; History of cancer; Obesity.
What are the side effects of Sermorelin?
Common mild side effects include: Flushing, Injection site reaction, Mild dizziness. Moderate effects: Headache, Nausea, Drowsiness.
What peptides stack well with Sermorelin?
Sermorelin is commonly stacked with: Ipamorelin, GHRP-2, GHRP-6, CJC-1295.
How do you reconstitute Sermorelin?
Sermorelin is reconstituted with bacteriostatic water. Exact volumes, concentrations, and units-to-draw calculations are available in the ClinPep Clinical plan. Always follow your compounding pharmacy's instructions.
How long should you cycle Sermorelin?
Sermorelin cycle protocols vary by indication. Detailed cycle length, on/off schedules, and monitoring guidelines are available with ClinPep Clinical access. Consult your healthcare provider for personalized cycling guidance.
References & Citations
10 PubMed studies · 3 clinical trials
Analysis of growth hormone releasing hormone and its analogs in urine using nano liquid chromatography coupled with quadrupole/orbitrap mass spectrometry.
Uçaktürk Ebru, Nemutlu Emirhan. Journal of pharmaceutical and biomedical analysis. 2026
Growth hormone-releasing hormone (GHRH) and its synthetic analogs are considered performance-enhancing substances and are therefore prohibited by the World Anti-Doping Agency (WADA). The analysis of G
Growth hormone - releasing hormone antagonists induce autophagy in cancer cells.
Sigdel Madan, Fakir Saikat, Sarker Md Matiur Rahman, Barabutis Nektarios. Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society. 2025
GHRH antagonists (GHRHAnt) were developed to suppress cancers and have been associated with robust anti-inflammatory and anti-oxidative activities. The mechanisms involved in those effects are not com
Growth Hormone-Releasing Hormone Antagonists Increase Radiosensitivity in Non-Small Cell Lung Cancer Cells.
Gesmundo Iacopo, Pedrolli Francesca, Giglioli Francesca Romana, Jazaj Florian et al.. International journal of molecular sciences. 2025
Growth hormone-releasing hormone (GHRH) antagonists exert antitumor functions in different experimental cancers. However, their role in combination with radiotherapy in non-small cell lung cancer (NSC
Antagonist of Growth Hormone-Releasing Hormone Receptor MIA-690 Suppresses the Growth of Androgen-Independent Prostate Cancers.
Muñoz-Moreno Laura, Gómez-Calcerrada M Isabel, Arenas M Isabel, Carmena M José et al.. International journal of molecular sciences. 2024
The development of resistance remains the primary challenge in treating castration-resistant prostate cancer (CRPC). GHRH receptors (GHRH-R), which are coupled to G-proteins (GPCRs), can mediate EGFR
A novel approach for the treatment of AML, through GHRH antagonism: MIA-602.
Costoya Joel, Gaumond Simonetta I, Chale Ravinder S, Schally Andrew V et al.. Reviews in endocrine & metabolic disorders. 2025
Acute myeloid leukemia (AML) is the most aggressive and prevalent form of leukemia in adults. The gold-standard intervention revolves around the use of chemotherapy, and in some cases hematopoietic st
Exploring the role of GHRH antagonist MIA-602 in overcoming Doxorubicin-resistance in acute myeloid leukemia.
Gaumond Simonetta I, Abdin Rama, Costoya Joel, Schally Andrew V et al.. Oncotarget. 2024
Acute myeloid leukemia (AML) is characterized by the rapid proliferation of mutagenic hematopoietic progenitors in the bone marrow. Conventional therapies include chemotherapy and bone marrow stem cel
Growth hormone-releasing hormone receptor antagonist MIA-602 attenuates cardiopulmonary injury induced by BSL-2 rVSV-SARS-CoV-2 in hACE2 mice.
Condor Capcha Jose M, Kamiar Ali, Robleto Emely, Saad Ali G et al.. Proceedings of the National Academy of Sciences of the United States of America. 2023
COVID-19 pneumonia causes acute lung injury and acute respiratory distress syndrome (ALI/ARDS) characterized by early pulmonary endothelial and epithelial injuries with altered pulmonary diffusing cap
In-house standards derived from doping peptides: Enzymatic and serum stability and degradation profile of GHRP and GHRH-related peptides.
González-López Nicolás Mateo, Guerra-Acero-Turizo Luisa María, Blanco-Medina Isabella, Barragán-Cárdenas Andrea Carolina et al.. Biomedical chromatography : BMC. 2023
Matrix effect and sample pretreatment significantly affect the percentage recovery of peptides in biological matrices, affecting the method robustness and accuracy. To counteract this effect, an inter
Registered Clinical Trials
Egrifta Replacement and Sleep Disordered Breathing
VRS-317 in Adult Subjects With Growth Hormone Deficiency
Tesamorelin as an Adjunct to Exercise for Improving Physical Function in HIV
Symptom Indications
Full Clinical Access
Complete Sermorelin Protocol
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This information is for educational and research reference purposes only. ClinPep does not provide medical advice, diagnosis, or treatment recommendations. All protocols should be reviewed by a licensed healthcare provider.