What Sermorelin is
Sermorelin is GHRH(1–29): the first 29 residues of growth-hormone-releasing hormone, and the shortest fragment that retains full receptor activity. Native GHRH is 44 residues; the finding that residues 30–44 are dispensable is itself a significant result, and sermorelin is the practical expression of it. Every other GHRH analogue in this catalogue is a modification of this scaffold.
- SermorelinGHRH(1-29), the shortest fully active fragment
- GHRH receptorPituitary somatotrophs
- Gs → cAMP → PKAPreserves pulsatile release, unlike exogenous GH
- GH axis modelsClinical diagnostic use
Mechanism as described in published research. Nothing here describes an effect in a person — these compounds are supplied for laboratory research use only.
GHRH-receptor signalling
Sermorelin is an agonist at the GHRH receptor on pituitary somatotrophs, acting through the physiological pathway rather than around it. Its limitation is stability: like native GHRH it is cleaved rapidly by dipeptidyl peptidase-4 at the N-terminus, giving it a short usable window.
That limitation is what the other analogues address, and comparing them is instructive. Modified GRF(1–29) substitutes four residues to resist cleavage while keeping the same length. CJC-1295 with DAC adds a linker that binds serum albumin, extending the window dramatically. Tesamorelin takes the longer GHRH(1–44) and blocks cleavage with an N-terminal acyl group. Four molecules, one receptor, four different answers to the same stability problem — which makes them a useful set for study design.
What the literature covers
Research areas include:
- Minimal-fragment pharmacology — what GHRH(1–29) retains.
- GHRH-receptor binding and downstream cAMP signalling.
- Comparative stability against modified and acylated analogues.
- Pulsatile versus sustained stimulus — short-acting analogues preserve pulsatility that longer-acting ones flatten.
Identity and verification
Sermorelin has the molecular formula C149H246N44O42S and a molecular weight of 3357.9 g/mol (CAS 86168-78-7). Identifiers matter more here than in most categories: research compounds are sold under trade names, development codes and abbreviations that do not always refer to the same molecule, and a formula is unambiguous where a name is not.
Every lot is tested by an independent laboratory before release. Our certificate library covers the lots currently in stock.
We use two laboratories because purity and identity are different questions. Vanguard Laboratory is ISO/IEC 17025:2017 accredited (A2LA #6377.01.01) and reports chromatographic purity and net quantity with a stated measurement uncertainty. Freedom Diagnostics reports HPLC-UV purity together with LC-MS identity confirmation — the test that catches a substituted compound rather than merely an impure one. A sample can be 99% pure and still be the wrong molecule. How we test →
Handling, reconstitution and storage
Sermorelin ships lyophilized — freeze-dried to a solid and sealed under vacuum — which is what makes it stable in transit rather than a solution racing a clock. Reconstitute with bacteriostatic water, added slowly down the inside wall of the vial rather than directly onto the powder, then swirled gently. Do not shake: mechanical shear is one of the few things that reliably degrades a peptide in the lab.
Final concentration is a function of the volume added, not of the compound, so the same vial can be prepared at very different concentrations. The reconstitution calculator works out the volume for a target concentration and the reconstitution guide covers the procedure. Store lyophilized vials at −20 °C (−4 °F) protected from light; refrigerate once in solution, and see the storage and stability guide for how long reconstituted material holds.
Common questions
What is sermorelin?
GHRH(1–29) — the first 29 residues of growth-hormone-releasing hormone, and the shortest fragment retaining full receptor activity. Native GHRH is 44 residues.
How does sermorelin differ from CJC-1295?
Modified GRF(1–29), sold as CJC-1295 without DAC, is the same length with four substitutions that resist enzymatic cleavage. CJC-1295 with DAC adds an albumin-binding linker on top of that. Sermorelin is the unmodified fragment, so it acts at the same receptor with a much shorter window.
Why would a study use the shorter-acting analogue?
Because the GH axis is naturally pulsatile. A short-acting stimulus preserves that pattern where a long-acting one flattens it, and for some questions the pulsatility is the variable of interest.
Do sermorelin and tesamorelin act on the same receptor?
Yes, both are GHRH-receptor agonists. They differ in length and in how they resist degradation — tesamorelin is based on GHRH(1–44) with an N-terminal acyl group.
Where to get it
Buy research-grade Sermorelin — independently tested, certificate published, shipped from Miami with cold-chain packaging. Current pricing for every size is on the price list, and we ship worldwide.
Research use only
Everything referenced here is supplied strictly for laboratory research. These compounds are not drugs, foods, cosmetics or medical devices, are not for human or veterinary use, and are not approved for diagnostic or therapeutic application. Mechanisms are described as studied in preclinical and laboratory research; nothing above describes dosing, treatment or clinical outcome.
