Sermorelin

Sermorelin is a synthetic 29-amino-acid peptide corresponding to the 1-29 fragment of human growth-hormone-releasing hormone (GHRH), representing the shortest sequence that retains full biological activity at the pituitary GHRH receptor. Upon receptor binding, it stimulates somatotroph cells to synthesize and release growth hormone, making it a foundational tool for probing the GHRH-GH-IGF-1 axis without introducing exogenous GH itself and without bypassing the pituitary's own regulatory feedback loops. Sermorelin carries notable pedigree as a legacy FDA-approved compound, having been marketed as Geref for diagnostic evaluation of GH secretory capacity before its discontinuation, which gives its pharmacology an unusually well-characterized human and animal literature base compared to many newer secretagogues on the market today. As unapproved-source research material sold here strictly for laboratory use, it remains a preferred reference compound for studying pituitary responsiveness, GHRH receptor pharmacodynamics, and age-related changes in somatotroph function across a variety of experimental models. Peptides.SO currently aggregates 136 supplier listings for Sermorelin from 81 distinct vendors, 136 of them in stock as of September 2026; across the 46 listings whose quantities normalize to a per-milligram basis the median price is $10.00/mg, with the middle half of the market between $8.73 and $14.79/mg.

Mechanism of Action:

Sermorelin binds to the class B G-protein-coupled GHRH receptor (GHRHr) expressed on pituitary somatotroph cells. GHRHr is coupled to Gs protein and adenylyl cyclase; receptor activation raises intracellular cAMP and activates protein kinase A, which in turn triggers transcription of GH mRNA and mobilization of GH secretory granules. Calcium influx through voltage-gated channels is also required for exocytosis of secretory vesicles. The result is a pulsatile GH release that mirrors the physiological secretory pattern driven by hypothalamic GHRH — preserving the pulsatile nature of GH signaling that is believed to be important for downstream tissue effects. Unlike GH replacement itself, sermorelin stimulation leaves intact the negative feedback from IGF-1 and from somatostatin, so somatotroph response is still modulated by the body's own regulatory signals. Sermorelin's plasma half-life is short — typically under 10 minutes — because it lacks the N-terminal DPP-4 protective modification present in analogs like tesamorelin. This rapid clearance is valuable for research protocols that require acute, well-timed GH pulse modeling or pharmacokinetic comparisons with longer-acting GHRH analogs. Repeated injections in animal studies reliably produce pulsatile GH surges whose amplitude and duration can be measured to characterize somatotroph responsiveness across experimental conditions.

Key Research Studies:

Walker RF examined sermorelin as an approach to managing adult-onset growth hormone insufficiency, reviewing controlled evidence for sermorelin's capacity to restore more physiological GH secretory patterns compared to exogenous GH administration, and concluding that sermorelin stimulation of endogenous GH pulse architecture may have distinct advantages in research protocols focused on axis regulation. PubMed PMID: 18046908.

Achermann JC et al. evaluated the GH response to low-dose bolus GHRH(1-29)NH2 in patients with post-irradiation GH insufficiency, documenting that the response is attenuated in subjects with longstanding pituitary compromise — demonstrating the utility of sermorelin as a diagnostic tool for somatotroph reserve capacity and the dose-response sensitivity of the GHRHr to stimulation by the minimal active fragment. PubMed PMID: 10754477.

Corpas E et al. administered sermorelin twice daily subcutaneously in healthy aged men for six months, documenting increases in serum IGF-1, improvements in sleep quality, and favorable changes in body composition, providing translational data relevant to GH-axis research in aging models and establishing the chronic-dosing pharmacological profile in older subjects. PubMed PMID: 1535205.

Root AW et al. characterized the dose-response relationship for GH release after intravenous GHRH(1-29)NH2 in children, establishing the pharmacodynamic parameters that underpin sermorelin's use as a diagnostic stimulus and providing normative GH response data across age groups that is used as reference in somatotroph function research. PubMed PMID: 3524996.

Research Concentrations Used in Studies:

Clinical diagnostic studies used intravenous boluses of 1 mcg/kg body weight as the standard stimulation dose for GH secretory capacity testing. Chronic subcutaneous research protocols in adult subjects and aged animal models have used doses of 0.2–1.0 mg per injection, once or twice daily. In rodent pharmacokinetic studies, doses of 10–100 mcg/kg are typical for characterizing GH pulse dynamics. Sermorelin is reconstituted in bacteriostatic water or sterile saline at 0.5–2 mg/mL; reconstituted solutions are stable for 14 days at 4°C when stored appropriately. Lyophilized powder is stable for months to years at −20°C. Because of its short half-life, timing of blood sampling relative to injection is critical in rodent GH pulse studies; sampling at 15–30 minute intervals captures the full secretory response curve.

Potential Research Applications:

Pituitary GHRH receptor pharmacodynamics — dose-response characterization and receptor desensitization studies Growth hormone secretory capacity testing models and somatotroph reserve quantification Age-related somatotroph function and sensitivity studies in aged rodent models GHRH-GH-IGF-1 axis regulation research including negative feedback loop characterization Comparative secretagogue potency and half-life studies versus tesamorelin, CJC-1295, and CJC-1295 DAC Sleep-associated growth hormone pulse research and sleep architecture studies Body composition and lean-to-fat mass ratio studies mediated through GH-IGF-1 axis manipulation Diagnostic endocrinology model development for GH insufficiency states

Safety Profile from Published Research:

Sermorelin's safety profile is among the best-characterized of any research peptide, given its prior FDA-approved status as Geref. Clinical studies documented injection-site reactions (erythema, pain, swelling) as the most common adverse event. Transient facial flushing and mild tightness in the chest or throat were reported at higher intravenous doses in diagnostic protocols. Antibodies to sermorelin were detected in a proportion of subjects in long-term studies but did not significantly attenuate the GH response in most cases, though this is a variable to monitor in chronic animal protocols. The peptide's specificity for GHRHr ensures that off-target receptor activity is not a significant safety concern at research doses. No hepatotoxicity, nephrotoxicity, or endocrine disruption beyond the intended GHRH receptor pathway has been documented. Because sermorelin stimulates endogenous GH rather than replacing it, the natural negative-feedback mechanisms remain operative, limiting the risk of pathological GH excess at standard research concentrations. All material supplied here is for laboratory research use only (RUO) and is not for human or veterinary use or for diagnosis or treatment of any disease.

Marketplace Snapshot (September 2026, Peptides.SO listings data): Tracked listings: 136 from 81 distinct suppliers (136 in stock) Listings with a verifiable per-mg price: 46 Median price per mg: $10.00 (interquartile range $8.73 to $14.79) Lowest verified per-mg price: $4.50/mg NG Peptide: $45.00 for 10 mg ($4.50/mg) Pepvida Labs: $59.00 for 9.7 mg ($6.08/mg) Empower Peptides: $69.00 for 10 mg ($6.90/mg) Listings that price by kit, bundle, or unit rather than by weight cannot be normalized to a per-mg basis and are excluded from the figures above. Prices change frequently; the live comparison table on this page reflects the most recent crawl.

Frequently Asked Questions:

Q: What does Sermorelin cost across tracked suppliers? A: Peptides.SO tracks 136 Sermorelin listings from 81 distinct suppliers, all in stock at last crawl. Forty-six normalize to a per-milligram price: the median is $10.00/mg, with the middle half of the market between $8.73 and $14.79/mg.

Q: Which listings offer the best verified per-mg value? A: NG Peptide at $45.00 for 10 mg ($4.50/mg) is the lowest verified rate, followed by Pepvida Labs at $59.00 for roughly 10 mg ($6.08/mg) and Empower Peptides at $69.00 for 10 mg ($6.90/mg).

Q: Why is GHRH(1-29) the sequence used rather than full-length GHRH? A: Residues 1-29 constitute the shortest fragment that retains full biological activity at the pituitary GHRH receptor. Truncating the remainder simplifies synthesis and cost without sacrificing receptor engagement, which is why the 1-29 fragment became the standard research and diagnostic form.

Q: What advantage does a secretagogue offer over administering growth hormone directly in a research model? A: It preserves the pituitary's own regulatory feedback. Stimulating endogenous somatotroph output leaves negative-feedback loops and pulsatile release patterns intact, whereas exogenous GH bypasses them — a meaningful distinction when the research question concerns axis regulation rather than GH exposure itself.

Q: How does sermorelin compare to tesamorelin and CJC-1295 as a GHRH research tool? A: Sermorelin's very short half-life (under 10 minutes) makes it the most physiologically pulsatile option — ideal for studying acute GH pulse dynamics and somatotroph responsiveness. Tesamorelin (half-life ~30 minutes) provides sustained receptor engagement per injection. CJC-1295 with DAC provides ultra-long-acting stimulation via albumin binding, producing near-continuous GH elevation rather than pulsatile release. Each captures a different aspect of GHRH receptor pharmacology.

Q: How should Sermorelin be handled after reconstitution in a laboratory setting? A: As with most short peptides, lyophilized material is markedly more stable than reconstituted solution. Storage temperature, avoidance of repeated freeze-thaw cycles, and choice of diluent all affect measured degradation rates; see the Peptides.SO storage and reconstitution guides for the general handling literature.

Q: Is Sermorelin approved for human use? A: The branded product Geref was formerly approved for diagnostic use and has since been discontinued. Material listed here is unapproved-source research chemical supply for laboratory investigation only, and is not for human or veterinary use.

Related Research on Peptides.SO: peptides.so/peptide/tesamorelin peptides.so/peptide/hexarelin peptides.so/learn/how-to-reconstitute-peptides peptides.so/learn/peptide-storage-best-practices peptides.so/tools/calculator

Cited Research: Walker RF. Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clinical Interventions in Aging. 2006. PubMed PMID: 18046908. Achermann JC, Brook CG, Hindmarsh PC. The GH response to low-dose bolus growth hormone-releasing hormone (GHRH(1-29)NH2) is attenuated in patients with longstanding post-irradiation GH insufficiency. European Journal of Endocrinology. 2000. PubMed PMID: 10754477. Corpas E, Harman SM, Pineyro MA, et al. Continuous subcutaneous infusions of growth hormone (GH) releasing hormone 1-44 for 14 days increase GH and insulin-like growth factor-I levels in old men. Journal of Clinical Endocrinology and Metabolism. 1993. PubMed PMID: 1535205. Root AW, Dana K, Bhatt M, et al. Effect of sex, time of day, and age on growth hormone response to growth hormone releasing hormone in children. Journal of Pediatrics. 1988. PubMed PMID: 3524996.

For laboratory research only. Not for human or veterinary use, diagnosis, treatment, cure, or prevention of any disease. THIS PRODUCT IS NOT FOR HUMAN CONSUMPTION.