Sermorelin

Educational overview

Sermorelin is listed in the ezGLP knowledgebase under GH secretagogue. Evidence and regulatory status can vary by formulation, route, and jurisdiction.

Sermorelin is a synthetic peptide consisting of the first 29 amino acids of human growth hormone-releasing hormone (GHRH), the shortest fragment that retains the full biological activity of the native 44-amino-acid hormone. It belongs to the GHRH-analogue class together with tesamorelin and CJC-1295 and acts on GHRH receptors in the anterior pituitary to stimulate synthesis and pulsatile release of growth hormone, with the response remaining subject to negative feedback from IGF-1 and somatostatin. Sermorelin acetate was marketed by Serono under the brand Geref, both as a diagnostic agent and as a treatment for children with idiopathic growth hormone deficiency.

Unlike most compounded secretagogues, sermorelin passed through a full regulatory development program. Prakash and Goa's 1999 review in BioDrugs summarised paediatric trials showing increased growth velocity in growth hormone-deficient children, generally less than that achieved with recombinant growth hormone, and a favourable tolerability profile dominated by injection-site reactions. Its half-life after subcutaneous injection is short, on the order of ten to twenty minutes, so the GH pulse it produces is brief. Adult data are sparse: Walker's 2006 review argued for its use in adult-onset GH insufficiency, but controlled trials of body composition, sleep, or aging outcomes in adults have not been published.

Geref was approved by the FDA in 1990 as a diagnostic and in 1997 as a paediatric treatment, and EMD Serono discontinued it in 2008; the FDA later determined in 2013 that the withdrawal was not for reasons of safety or effectiveness, and the product remains listed as discontinued. No sermorelin product is currently approved in the United States, the European Union, or comparable jurisdictions, so it is available only from compounding pharmacies. Because sermorelin acetate was the active ingredient of an approved product, its compounding status differs from that of never-approved peptides, and the FDA's 2024 advisory committee materials on ipamorelin noted that Geref remains the only growth hormone secretagogue ever approved for paediatric growth hormone deficiency. The World Anti-Doping Agency names sermorelin explicitly on its Prohibited List under section S2.2.4, banned at all times.

Compounded sermorelin is supplied as a lyophilised powder that is reconstituted with bacteriostatic water for subcutaneous injection, often at bedtime to coincide with the nocturnal GH pulse, and it is frequently blended in a fixed ratio with ipamorelin. The original Geref labelling called for refrigeration of the reconstituted solution and discard after a limited period, but compounded products follow the dispensing pharmacy's beyond-use dating rather than the discontinued label. Dose logs for sermorelin commonly record lot number, reconstitution date, concentration produced, and storage temperature, and, because the peptide is short-acting and dosed in relation to sleep, the clock time of administration.

Category

GH secretagogue

Routes represented

Subcutaneous (SubQ)

Approximate library half-life

0.2 hours; formulation-dependent and not dosing guidance

Storage context

Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.