Sermorelin

What is Sermorelin

Sermorelin is a synthetic 29-amino-acid peptide identical to the first 29 residues of human growth-hormone-releasing hormone. The full GHRH molecule is 44 amino acids long, but the 1-29 fragment carries the entire active site, which is why sermorelin behaves like native GHRH at the receptor.

It was developed in the 1980s and approved by the FDA in the 1990s under the brand name Geref, first for diagnosing growth-hormone deficiency in children and later for treating it. The product was pulled from the US market in 2008 by its manufacturer for commercial reasons, after recombinant GH became the dominant pediatric therapy. The FDA later confirmed the withdrawal was not based on safety or efficacy concerns.

We supply it as research-grade lyophilized powder.

How it works

Sermorelin binds the GHRH receptor on somatotroph cells in the anterior pituitary. That receptor is a class B G-protein-coupled receptor: activation raises intracellular cAMP, switches on protein kinase A, and produces two effects in parallel. First, GH already stored in secretory granules is released into the bloodstream within minutes. Second, transcription of the GH gene is upregulated, refilling the pituitary's GH reserve over time.

Because the signal acts upstream of the pituitary, the rest of the axis stays intact. Somatostatin and circulating IGF-1 still feed back to throttle GH output, so the resulting GH pulses look like the body's own pulses rather than the flat exposure produced by injecting recombinant GH directly.

GH released from the pituitary travels to the liver, where it drives production of IGF-1, the main mediator of GH's downstream effects. GHRH output and the size of GH pulses both decline with age (somatopause), and that decline shows up as lower circulating IGF-1. In published clinical research, daily GHRH 1-29 dosing in older adults restored 24-hour GH and IGF-1 toward levels seen in younger subjects, with effects on body composition and skin thickness reported over multi-month studies.

Often studied alongside

Sermorelin is most often paired in research protocols with a growth-hormone secretagogue that works on a different receptor. Ipamorelin is the cleanest pairing: it acts on the ghrelin/GHS receptor and amplifies the GH pulse without affecting cortisol or prolactin. Pre-blended CJC-1295 + ipamorelin is the most commonly studied combination in this class. Tesamorelin, a stabilized GHRH analog, is the closest relative and is studied in similar IGF-1 and body-composition contexts.

For reconstitution, the standard solvent in published protocols is bacteriostatic water.

Documentation