Educational reference, not medical advice. This page summarizes information from published research and regulatory filings for educational purposes. It is not a recommendation to use any compound and should not replace guidance from a licensed healthcare provider. Most peptides discussed here are not approved for the uses described.
What it is
Sermorelin is a synthetic peptide consisting of the first 29 amino acids of human growth hormone-releasing hormone (GHRH) — the smallest fragment of the native 44-amino-acid hormone that retains full biological activity. It activates the GHRH receptor on pituitary somatotrophs and triggers pulsatile growth hormone release.
It is the parent compound from which several later GHRH analogs (Mod GRF 1-29, CJC-1295) were derived. Those later molecules carry additional substitutions intended to extend the very short half-life of unmodified sermorelin.
History
The native GHRH peptide was isolated in 1982 from a pancreatic tumor by Roger Guillemin's group at the Salk Institute. The 1-29 fragment was identified the same year as the minimum sequence required for activity, and Serono (then Hoffmann-La Roche's GHRH partner) developed it into the drug Geref. Key milestones:
- 1990 — Geref approved as a diagnostic agent for the GHRH stimulation test.
- 1997 — FDA approves Geref (sermorelin acetate, 0.5 mg vials) for treatment of idiopathic growth hormone deficiency in children. The 1999 BioDrugs review by Prakash and Goa summarizes the pediatric trial program.
- 2008 — Serono withdraws Geref from the U.S. market. The withdrawal letter to FDA cited commercial reasons, not safety or efficacy concerns.
Since 2008 sermorelin has been available in the United States only through compounding pharmacies. It remains on the FDA's 503A bulk substances list under Category 1 (substances eligible for compounding), in contrast to BPC-157 which was placed in Category 2 in 2023.
Regulatory status
Sermorelin acetate held FDA approval as Geref from 1997 until its 2008 commercial withdrawal. No branded sermorelin product is currently marketed in the United States. Compounding pharmacies may prepare it under Section 503A of the Federal Food, Drug, and Cosmetic Act for individual prescriptions.
The European Medicines Agency has not authorized sermorelin. The World Anti-Doping Agency lists GHRH and its analogs under class S2 of the Prohibited List — banned in and out of competition.
Mechanism
Sermorelin acts as a GHRH receptor agonist on anterior pituitary somatotrophs. Receptor binding elevates intracellular cAMP and stimulates pulsatile growth hormone release. Because sermorelin mirrors native GHRH activity, the resulting GH pulse remains under negative feedback from somatostatin — meaning peak GH is constrained by endogenous counter-regulation, in contrast to ghrelin-receptor agonists that act on a separate pathway.
In the pediatric GHD program, daily evening subcutaneous injection of sermorelin was shown to increase height velocity in children with documented GH deficiency, with the response generally more modest than recombinant GH but with a more physiological GH secretion pattern.
Half-life and dosing intervals
The published plasma half-life of sermorelin is short — 10 to 20 minutes after subcutaneous injection. The brief exposure window is what preserves natural pulsatile GH secretion and is also why the molecule was later modified (with substitutions or albumin-binding tags) to produce longer-acting analogs.
The Geref pediatric label specified 0.03 mg/kg subcutaneously once daily at bedtime for children with idiopathic GHD. In adult observational use, doses are typically in the 200 to 500 mcg range administered once nightly. Adult doses are not based on a regulatory program; they are extrapolated from the pediatric label and from observational reports.
Reconstitution example
Compounded sermorelin is supplied lyophilized in 2 mg, 5 mg, or 15 mg vials. A 5 mg vial reconstituted with 2.5 mL of bacteriostatic water yields 2 mg/mL — on a 1 mL U-100 insulin syringe, 10 units (0.1 mL) contains 200 mcg.
A 15 mg vial reconstituted with 3 mL of bacteriostatic water yields 5 mg/mL — 10 units then contains 500 mcg. Vial's calculator handles the unit-to-microgram conversion automatically when you enter the vial mass and water volume.
What to know
- Historical FDA approval. Sermorelin held approval for pediatric GHD from 1997 to 2008; the withdrawal was commercial, not safety-driven.
- No approved branded product. Current U.S. availability is through compounding pharmacies under 503A.
- WADA banned. Use is prohibited in competitive sport.
- Reported side effects in the Geref program included injection-site reactions (the most common), headache, flushing, dysgeusia (taste alteration), and rare hypersensitivity. Cortisol and prolactin are not significantly affected.
- Short half-life preserves pulsatility. Sermorelin produces a brief, physiological GH pulse rather than the sustained elevation seen with long-acting analogs.
- Storage. Lyophilized vials are best stored refrigerated. Once reconstituted, refrigerate and use within the stability window specified by the compounder — typically 4 weeks for bacteriostatic-water reconstitution.
Sources
- 1.Prakash A, Goa KL (1999). Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency. BioDrugs.
- 2.Walker RF (2006). Sermorelin: a better approach to management of adult-onset growth hormone insufficiency? Clinical Interventions in Aging.
- 3.Sigalos JT, Pastuszak AW (2018). The Safety and Efficacy of Growth Hormone Secretagogues. Sexual Medicine Reviews.
- 4.FDA Drugs@FDA — Geref (sermorelin acetate) approval history.
- 5.World Anti-Doping Agency — Prohibited List (S2).