Sermorelin
FDA-approvedShort-acting GHRH(1-29) analog
Also known as: GRF 1-29, GHRH (1-29), Geref
Sermorelin is a GHRH analog made of the first 29 amino acids of growth-hormone-releasing hormone — the shortest fragment that retains full activity. It was FDA-approved for diagnostic and therapeutic use before being commercially discontinued.
Molecular & research data
- Sequence
- GRF(1-29)-NH2 (first 29 residues of human GHRH)
- CAS number
- 86168-78-7
- Molecular formula
- C149H246N44O42S
- Molecular weight
- 3357.9 g/mol
- Half-life
- ≈10–20 minutes
- Primary targets
- GHRH receptor
- Routes (research)
- Subcutaneous
- Storage
- Lyophilised: −20 °C. Reconstituted: 2–8 °C, use within weeks.
Overview
Sermorelin is a synthetic analog of growth-hormone-releasing hormone (GHRH), consisting of the hormone’s first 29 amino acids — known as GRF 1-29. This fragment is the smallest portion of GHRH that retains full biological activity, making Sermorelin a faithful, short-acting mimic of the natural hormone.
It holds a distinction among the peptides in this database: it was genuinely FDA-approved (marketed as Geref) for diagnostic evaluation of pituitary function and for pediatric growth hormone deficiency, before being withdrawn from the market for commercial rather than safety reasons.
Mechanism of action
Sermorelin binds the GHRH receptor on the anterior pituitary, stimulating the natural synthesis and pulsatile release of growth hormone. Because it works through the body’s own regulatory machinery, GH release remains subject to normal feedback — including suppression by somatostatin — which is part of its appeal as a physiological approach.
Its very short half-life (minutes) produces a sharp, natural-shaped GH pulse, in contrast to the sustained exposure from long-acting analogs like CJC-1295.
Common research uses
- Diagnostic testing of pituitary growth hormone reserve
- Research into age-related decline in GH secretion
- As the short-acting reference point in the GHRH-analog family, alongside Tesamorelin
Compare Sermorelin
Sermorelin FAQ
Is Sermorelin FDA-approved?+
Yes — it was approved (as Geref) for assessing growth hormone secretion and for pediatric growth hormone deficiency. The branded product was later discontinued for commercial reasons, not safety.
How is Sermorelin different from CJC-1295?+
Both are GHRH analogs, but Sermorelin is a short, unmodified fragment with a half-life of minutes, while CJC-1295 was engineered (with DAC) to last days.
What is GRF 1-29?+
GRF 1-29 is the first 29 amino acids of growth-hormone-releasing hormone. This is the minimal portion that retains the molecule's full ability to stimulate GH release, and it is what Sermorelin is.
References
Related peptides
CJC-1295
In clinical trialsLong-acting GHRH analog
CJC-1295 is a synthetic analog of growth-hormone-releasing hormone (GHRH) engineered for a dramatically extended half-life, studied for its ability to raise growth hormone and IGF-1 levels.
Tesamorelin
FDA-approvedFDA-approved stabilised GHRH analog
Tesamorelin is a stabilised GHRH analog and the only growth-hormone secretagogue with FDA approval specifically for reducing excess visceral fat (in HIV-associated lipodystrophy).
Ipamorelin
In clinical trialsSelective ghrelin-mimetic GHRP
Ipamorelin is a selective growth hormone releasing peptide (GHRP) that stimulates GH release with minimal effect on cortisol, prolactin, or appetite, making it the cleanest of the classic GHRPs.
Last reviewed: 2026-06-26. Information is provided for research and educational reference only — see our disclaimer.