Growth Hormone Secretagogue
Sermorelin
Also known as: GRF 1-29, GHRH(1-29)-NH2
The shortest fragment of growth-hormone-releasing hormone that retains full biological activity — formerly FDA-approved (as Geref, since discontinued commercially) for diagnosing and treating pediatric growth hormone deficiency, with a well-characterized human clinical record.
Overview
Sermorelin is a 29-amino-acid peptide corresponding to the shortest fragment of growth-hormone-releasing hormone (GHRH) that retains full biological potency. It was FDA-approved under the brand name Geref for diagnosing and treating growth hormone deficiency in children, though the original branded product was discontinued for commercial reasons (not safety) and generic/compounded versions have since been used off-label, including in adults, without the same level of clinical trial support.
Proposed Mechanism of Action
As a GHRH receptor agonist, sermorelin stimulates the pituitary to release endogenous growth hormone in a pulsatile pattern, mimicking natural GHRH signaling — distinguishing it mechanistically from GH secretagogues like ipamorelin or hexarelin that act through the separate ghrelin/GHS-R1a receptor pathway.
Research Context
The cited review synthesizes the pediatric clinical trial literature: sermorelin's use as a rapid diagnostic test for GH deficiency (single IV dose), and as a therapeutic growth-promoting agent in children with confirmed deficiency (daily subcutaneous dosing). Notably, the review reports that height-velocity outcomes with sermorelin were smaller than with equivalent-dose recombinant human growth hormone (somatropin) — useful context for weighing sermorelin against GH itself, not just against other secretagogues.
Limitations of the Current Evidence
- The strongest clinical evidence here is specifically in prepubertal children with diagnosed GH deficiency — a narrow, specific population. Off-label adult use (e.g., for anti-aging or body composition purposes) is not supported by the cited pediatric trial data.
- Sermorelin's plasma half-life is very short (roughly 11-12 minutes per the cited review), which has implications for how frequently and by what route it needs to be administered to sustain effect — a detail worth keeping in mind against any dosing protocol you encounter.
Research-Setting Dosing (as reported in literature)
| Route | Range (as reported) | Frequency | Notes |
|---|---|---|---|
| Intravenous (diagnostic use) | 1–1 µg/kg | Single dose | Used as a provocative test for growth hormone deficiency diagnosis in children — a rapid, relatively specific diagnostic tool per the cited review, not a treatment regimen. |
| Subcutaneous (therapeutic use) | 30–30 µg/kg | Once daily, at bedtime | Therapeutic regimen in prepubertal children with idiopathic GH deficiency; the review notes height-velocity gains with this regimen were smaller than with equivalent-dose somatropin (recombinant human growth hormone) therapy. |
Figures above are extracted directly from the cited preclinical/research literature. They describe what researchers administered to study subjects (frequently animal models) — they are not human dosing recommendations and are not medical advice.
Cited Studies
Sermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency
Prakash A, Goa KL · BioDrugs · 1999
Review of human clinical trialsView source →
Last updated August 1, 2026