Sermorelin is a 29-amino-acid peptide corresponding to the N-terminal fragment of growth hormone releasing hormone, often written GHRH(1-29)NH2. Researchers discovered that this shortened sequence retains the receptor activity of the full 44-residue hormone, which made it a foundational tool in GHRH receptor research. This overview covers sermorelin as a laboratory reagent: its structure, research themes, how it compares with modified GHRH analogs, and what documentation to expect.
Structure of Sermorelin
Sermorelin consists of the first 29 amino acids of native GHRH with a C-terminal amide. It contains no D-amino acids or non-natural residues, which distinguishes it from engineered analogs. Its molecular weight is approximately 3,358 Da, and at that length both HPLC purity and mass spectrometry identity are important, since truncated or deletion sequences from synthesis can be close in mass.
Because it is an unmodified native fragment, sermorelin is relatively susceptible to enzymatic cleavage, notably by dipeptidyl peptidase-4 at the N-terminus. That property is one reason later analogs were engineered with substitutions.
How Sermorelin Compares to Other GHRH Analogs
Sermorelin is often discussed alongside CJC-1295 and tesamorelin. CJC-1295 introduces four amino acid substitutions to the same 1-29 backbone to resist degradation, and the DAC version adds a lysine-linked maleimide group for albumin binding. Tesamorelin attaches a trans-3-hexenoyl group to the full 44-residue sequence. In receptor studies, sermorelin functions as the closest-to-native reference point against which these modifications can be compared. See CJC-1295 DAC vs No DAC and the Tesamorelin overview for more.
Common Laboratory Research Themes
- GHRH receptor pharmacology: using sermorelin as a native-sequence reference agonist.
- Structure-activity studies: comparing native and substituted 1-29 fragments.
- Peptide stability research: measuring enzymatic degradation rates in vitro.
- Receptor co-signaling: studying GHRH receptor and GHS-R interactions in cell models.
Sermorelin Specifications at a Glance
- Class: GHRH(1-29) fragment
- Length: 29 amino acids, C-terminal amide
- Form: lyophilized powder
- Size: 10mg vial
- Verification: HPLC purity and mass spectrometry identity, third-party tested
Quality Documentation for Sermorelin
For any Sermorelin lot, the most useful document is the Certificate of Analysis. A credible COA identifies the lot number, the analytical method used for purity (typically reversed-phase HPLC with UV detection), the observed molecular mass from mass spectrometry, and the date of testing. If you are new to this, our guide on how to read a peptide Certificate of Analysis walks through each field, and our explainer on HPLC and mass spectrometry purity testing covers why the two methods are complementary.
Genetic Peptides USA lots are independently tested through PepAssure third-party verification, so the identity and purity numbers on the label can be traced back to a specific batch. Researchers comparing suppliers should confirm that the COA lot matches the vial lot, that the mass spectrum is consistent with the theoretical mass, and that purity is reported as a chromatographic area percentage rather than an unexplained single number.
Storage and Stability Considerations
Sermorelin is supplied as a lyophilized (freeze-dried) powder. In that form, peptides are generally most stable when kept cold, dry, and protected from light, and repeated temperature cycling should be avoided. Once a lyophilized peptide is brought into solution for an assay, stability characteristics change, so many labs prepare only what a given experiment requires and document preparation dates carefully. Our article on lyophilized peptide handling and storage covers general laboratory practices for freeze-dried research materials.
Where to Go Next
Review lot details on our Sermorelin 10mg research peptide page or browse the GH Axis Research collection for related GHRH analogs and GHRPs.
Frequently Asked Questions
What is sermorelin?
Sermorelin is the 29-amino-acid N-terminal fragment of growth hormone releasing hormone, GHRH(1-29)NH2, used as a reference agonist in GHRH receptor research.
How does sermorelin differ from CJC-1295?
Both share the 1-29 backbone, but CJC-1295 adds four amino acid substitutions for stability, while sermorelin keeps the native sequence.
Why is sermorelin susceptible to degradation?
As an unmodified native fragment it is cleaved by enzymes such as dipeptidyl peptidase-4 in experimental systems.
What molecular weight should a sermorelin COA show?
The observed mass should be consistent with approximately 3,358 Da, alongside HPLC purity and a matching lot number.
Is this product for human or animal use?
No. It is supplied for laboratory research use only and is not for human or veterinary use. It is not a drug, food, or cosmetic and is not intended to diagnose, treat, cure, or prevent any disease.
All products referenced in this article are sold strictly for laboratory research use only. They are not for human or veterinary use, are not drugs, foods, or cosmetics, and are not intended to diagnose, treat, cure, or prevent any disease. Nothing here is guidance on administration or handling outside a qualified laboratory setting.