Sermorelin
GHRH analog (growth-hormone-releasing hormone analog)
A 29-amino-acid analog of GHRH used in growth-axis research.
Also referenced as: GHRH (1-29), GRF 1-29, Sermorelin acetate
Overview
Sermorelin is a synthetic peptide corresponding to the first 29 amino acids of human growth-hormone-releasing hormone (GHRH 1-29), the shortest fully active fragment of GHRH. It was formerly marketed as Geref.
At a glance
What Sermorelin does
Sermorelin is a truncated analog of growth hormone-releasing hormone (GHRH), consisting of the first 29 amino acids of native GHRH (GRF 1-29) — the shortest fragment that retains full biological activity. It works on the classic GHRH axis: it binds GHRH receptors on pituitary somatotrophs, activating adenylate cyclase and cAMP signaling to stimulate both the synthesis and the pulsatile release of the body's own growth hormone. Because it drives endogenous GH rather than supplying GH directly, the resulting secretion follows the body's natural feedback loops — somatostatin and IGF-1 negative feedback still cap how much GH is released, which is why GHRH analogs are described as producing a more physiologic, self-limiting GH profile than exogenous GH.
Historically sermorelin was the most clinically developed of these peptides: it was FDA-approved (as Geref) as a diagnostic agent for pituitary GH reserve and studied for GH deficiency in children before being discontinued for commercial reasons. That gives it a stronger human evidence base than most peptides in this category. In studies it raises GH secretion and, over time, IGF-1, and it was used to probe whether a sluggish GH axis was pituitary-based or hypothalamic. Its very short half-life (minutes) means it acts as a brief trigger, preserving the pulsatile pattern of GH release rather than clamping GH high continuously.
Much of its modern use is off-label/research-framed for age-related GH decline; the rigorous outcome data are the older pediatric GH-deficiency and diagnostic-testing studies rather than anti-aging trials.
Effects reported in research
- Stimulated pituitary release of endogenous growth hormone via GHRH-receptor / cAMP signaling (established in human studies).
- Increased circulating IGF-1 with sustained administration in GH-deficient patients.
- Used clinically as a diagnostic test of pituitary GH secretory reserve (FDA-approved indication as Geref).
- Improved growth velocity in children with GHRH-responsive growth hormone deficiency (human clinical data).
- Preserved the natural pulsatile pattern of GH secretion because its action is brief and subject to normal feedback.
- Distinguished hypothalamic from pituitary causes of GH deficiency in diagnostic testing.
- Downstream GH/IGF-1 elevation studied for effects on lean mass and body composition, though anti-aging efficacy is not established in rigorous trials.
Effects listed reflect findings reported in the research literature — many in animal or in-vitro models. Listing an effect is not a claim of efficacy or a therapeutic indication in humans.
Mechanism of action
Sermorelin is an agonist of the GHRH receptor on anterior-pituitary somatotrophs, stimulating the synthesis and pulsatile secretion of endogenous growth hormone. Because it acts upstream and preserves physiologic feedback, GH release remains subject to somatostatin regulation. Its effect on the GH/IGF-1 axis is thereby more physiologic than direct GH administration.
Mechanistic description reflects published research-literature understanding. Much peptide research is preclinical (in-vitro or animal-model); mechanism in humans may differ and is not established for many compounds.
What it's studied for
Research contexts in which Sermorelin appears in the literature. Listing a research area is not a claim of efficacy or a therapeutic indication.
Key characteristics
- Comprises GHRH(1-29), the minimal biologically active GHRH fragment
- Acts at the GHRH receptor (distinct from the ghrelin/GHS receptor targeted by GHRPs)
- Very short plasma half-life due to rapid enzymatic (DPP-4) cleavage
- Preserves negative feedback via somatostatin, unlike exogenous GH
- Frequently studied in combination with GHRPs for additive GH release
Reported research dosing reference only
Educational reference, not dosing guidance. The figures below summarize amounts reported in published research and research-community protocols, provided for educational and research context only. They are not medical advice, not a recommendation, and not instructions for human use. Sermorelin is a research compound.
Research and historical clinical references cite sermorelin in the low-hundreds-of-micrograms per dose range, administered subcutaneously. These are reference figures for research context only, not dosing guidance for humans.
- Common research-protocol reference: 100-300 mcg per subcutaneous dose
- Historical GH-stimulation testing referenced ~1 mcg/kg as a diagnostic bolus
~11-12 min half-life due to DPP-IV cleavage; reference figures only, not human dosing guidance.
How it compares
Sermorelin is a GHRH-receptor agonist (GHRH 1-29) rather than a ghrelin-receptor GHRP, and it is shorter-acting than modified GHRH analogs such as CJC-1295 or tesamorelin.
Commonly studied alongside
Compounds frequently researched together with Sermorelin in the literature. Cross-referenced for research context — not a usage or combination recommendation.
Compare and calculate
Side-by-side pages for the pairings the literature already documents for Sermorelin, plus the unit-conversion reference for a reconstituted vial. Factual comparisons of documented characteristics — not a recommendation to combine or use any compound.
Handling & Stability
Lyophilized peptides are stored cold, protected from light, and reconstituted only at the time of intended in-vitro work.
- Avoid repeated freeze-thaw cycles
- Verify supplier lot and Certificate of Analysis
- Follow institutional lab-safety protocols
Analytical & COA Concepts
Reputable research suppliers publish a third-party Certificate of Analysis per batch. Key analytical concepts referenced in COAs include:
Category Context
Sermorelin sits in the Growth & GH-Axis area of the PeptiDex library.
- Entry type: Research compound reference
- Growth & GH-Axis category hub →
- Browse the full library →
- Glossary of terms →
Where researchers source Sermorelin
For researchers studying Sermorelin, third-party suppliers such as Practically Natty Peptides offer research-grade material, third-party tests every batch and provides Certificates of Analysis on request, and ship from the US. This specific listing is currently marked out of stock — check the supplier site for current availability.
View research-supplier listing →
Outbound link to a third-party research supplier. Inclusion does not constitute endorsement; all editorial content is developed independently.
Frequently asked questions
What is sermorelin?
Sermorelin is a synthetic 29-amino-acid peptide corresponding to the biologically active amino-terminal fragment (residues 1-29) of human growth hormone-releasing hormone (GHRH). It binds the GHRH receptor on the anterior pituitary and is studied for its ability to stimulate the body's own GH production.
How does sermorelin differ from CJC-1295?
Both are GHRH analogs based on the GRF(1-29) sequence, but sermorelin is the unmodified fragment with a very short (~11-12 minute) half-life, whereas CJC-1295 adds amino-acid substitutions (and, in the DAC version, albumin binding) to resist enzymatic breakdown and extend duration substantially.
Why does sermorelin have such a short half-life?
The native GRF(1-29) sequence is rapidly cleaved in plasma by dipeptidyl peptidase-IV (DPP-IV) between residues Ala2 and Asp3. This gives sermorelin a plasma half-life of only about 11-12 minutes, so research protocols model brief, physiologic GH pulses.
Is sermorelin an approved drug?
Sermorelin acetate was historically FDA-approved (as Geref) and used as a diagnostic agent for GH deficiency, but the branded product was later discontinued. It is now encountered primarily as a compounded or research-grade peptide rather than a currently marketed FDA product.
Why is sermorelin often studied with a GHRP?
Sermorelin acts on the GHRH receptor while GHRPs like ipamorelin or GHRP-2 act on the ghrelin receptor. Research pairing the two exploits the two complementary pathways to produce a larger, synergistic GH pulse than either alone.
Answers are educational summaries of research-literature context and do not constitute medical advice. See the Research Library, COA guide, and Storage & Handling guide for more.
References
Primary literature indexed in PubMed for Sermorelin. Listing a study records that it exists and is indexed — it is not a claim of efficacy, a therapeutic indication, or an endorsement of its conclusions. Much of this literature is preclinical (in-vitro or animal-model).
- Does growth hormone releasing factor desensitize the somatotroph? Interpretation of responses of growth hormone during and after 10-hour infusion of GRF 1-29 amide in man
- Catabolism of rat growth hormone-releasing factor(1-29) amide in rat serum and liver
Each reference was checked against its PubMed record on 2026-07-28: the PMID resolves and the title, journal and year match. Where no indexed literature exists for a compound, PeptiDex says so rather than substituting a citation about a different molecule. See the editorial policy.