Sermorelin
Sermorelin is a synthetic 29-amino-acid fragment of human growth hormone-releasing hormone (GHRH 1-29) that stimulates the pituitary to release growth hormone and was formerly FDA-approved (as Geref) for diagnosing and treating growth hormone deficiency before being discontinued from the market for commercial, not safety, reasons.
This page is a research-orientation summary, not a dosing guide. For anything beyond general background, read the primary literature or talk to a qualified clinician — specifics like amount, frequency, or administration aren't something we publish here.
What it does & how it works
Sermorelin binds the GHRH receptor on anterior pituitary somatotroph cell membranes, a Gs protein-coupled receptor that activates adenylate cyclase and raises intracellular cAMP, which in turn activates protein kinase A and stimulates transcription, synthesis, and pulsatile release of growth hormone. Because it retains the full biological activity of native GHRH within its first 29 residues, it works through the body's normal, hypothalamus-dependent feedback loop rather than delivering growth hormone directly, meaning pituitary somatotrophs must be functional for it to work. It is rapidly degraded by proteolytic enzymes, including dipeptidyl peptidase-4, giving native sermorelin a very short plasma half-life of only several minutes.
Typical results seen in research
In clinical use, sermorelin reliably raised growth hormone and IGF-1 levels and was used both as a diagnostic agent (GHRH stimulation test) to evaluate pituitary GH reserve and as a therapy for pediatric growth hormone deficiency, producing improved growth velocity in GH-deficient children in trials supporting its original FDA approval. Its short half-life necessitates more frequent dosing than longer-acting GHRH analogs, and evidence in healthy adults or for non-deficiency indications is comparatively limited relative to its pediatric GH-deficiency data.
How it’s commonly used
Sermorelin is administered by subcutaneous injection as an ongoing regimen in pediatric growth hormone deficiency, and has also been used as an intravenous or subcutaneous bolus for diagnostic GHRH stimulation testing of pituitary function. It is compounded and used off-label in some adult wellness/research settings following the discontinuation of the branded product.
- Proceedings of the National Academy of Sciences · 1984 Isolation, primary structure, and synthesis of human hypothalamic somatocrinin: growth hormone-releasing factor
Curated from published literature for research orientation. Not an exhaustive review, and not a substitute for reading primary sources.