Overview
What Is Sermorelin?
Sermorelin (GHRH 1-29 NH₂) is a synthetic 29-amino acid peptide corresponding to the biologically active N-terminal fragment of endogenous growth hormone-releasing hormone (GHRH). Endogenous GHRH is a 44-amino acid hypothalamic peptide — Sermorelin retains the receptor-binding domain responsible for GHRH's physiological effects while being shorter and more stable than the full-length sequence.
It acts as a selective agonist of the GHRH receptor (GHRHR), a Gs-coupled receptor expressed on pituitary somatotroph cells. Receptor activation increases intracellular cAMP, activates protein kinase A, and stimulates the pulsatile secretion of endogenous growth hormone — closely mimicking the natural hypothalamic GHRH pulse.
Format
5mg vial
Lyophilized powder
Receptor Target
GHRHR
GHRH receptor (Gs-coupled)
Half-Life
~10–20 min
Close to native GHRH kinetics
Sequence
GHRH (1-29) NH₂
29-amino acid N-terminal fragment
Category
Fitness & Performance
GH axis · GHRH analogue
🔬 Reconstitution Protocol
Reconstitute with
2.5 mL Bacteriostatic Water for a working concentration of 2 mg/mL. Inject diluent slowly along the vial wall — do not inject directly onto the powder or shake. Swirl gently until dissolved. Solution should be clear and colorless.
Refrigerate at 2–8°C after reconstitution. Stable for 28–42 days. See the
full reconstitution guide →
Mechanism
How Sermorelin Works
Sermorelin's mechanism is straightforward: it binds the GHRH receptor on anterior pituitary somatotrophs, activates the Gs → adenylyl cyclase → cAMP → PKA signaling cascade, and triggers GH release in a pulsatile pattern consistent with endogenous GHRH physiology.
Short half-life as a research feature: With a half-life of approximately 10–20 minutes, Sermorelin produces a discrete, time-limited GH pulse that closely mirrors the natural hypothalamic GHRH pulse. This makes it particularly useful in research protocols where investigators want to model native GHRH kinetics — as opposed to CJC-1295 with DAC (~6–8 day half-life), which produces sustained, tonic GHRHR occupancy and a fundamentally different GH secretion pattern.
Complementary to GHRPs: Sermorelin (GHRHR agonist) and GHRPs like Ipamorelin (GHSR-1a agonist) act on different receptors via different second-messenger systems. Sermorelin amplifies pulse amplitude via the GHRH pathway; Ipamorelin triggers GH release via the ghrelin receptor pathway. Researchers studying the convergent activation of both systems use both compounds together. See: Ipamorelin vs CJC-1295 comparison →
FAQ
Frequently Asked Questions
What is Sermorelin?
Sermorelin is a synthetic analogue of growth hormone-releasing hormone (GHRH) consisting of the first 29 amino acids of the 44-amino acid endogenous GHRH sequence. It acts on GHRH receptors in pituitary somatotroph cells to stimulate pulsatile growth hormone secretion.
How does Sermorelin differ from CJC-1295?
Both are GHRH analogues targeting the GHRH receptor. The key difference is half-life: Sermorelin has approximately 10–20 minutes (close to native GHRH), while CJC-1295 without DAC has ~30 minutes and CJC-1295 with DAC extends to 6–8 days. Sermorelin is preferred when close mimicry of endogenous GHRH pulse kinetics is required.
How do I reconstitute Sermorelin?
Reconstitute the 5mg vial with 2.5 mL Bacteriostatic Water for a 2 mg/mL working concentration. Inject gently along the vial wall and swirl. Refrigerate at 2–8°C after reconstitution. Stable 28–42 days refrigerated.
Is Sermorelin the same as Ipamorelin?
No. Sermorelin is a GHRH analogue that targets the GHRH receptor (GHRHR). Ipamorelin is a GHRP that targets the ghrelin receptor (GHSR-1a). They act through distinct receptors and distinct second-messenger cascades — they are complementary tools for studying different aspects of GH axis biology, not alternatives for the same experiment.