Sermorelin is the first 29 amino acids of human growth hormone-releasing hormone (GHRH), the part of the molecule that still does the whole job. Native GHRH is 44 residues long. Trim it down to residues 1 through 29 and add an amide cap, and you keep full activity at the receptor. That truncated peptide is sermorelin, also written as GRF(1-29)NH2 and registered under CAS number 86168-78-7.
It belongs to the GHRH-analog family. Drugs in this class don't supply growth hormone directly. They tell the pituitary to make and release its own.
How it works
Sermorelin binds the growth hormone-releasing hormone receptor (GHRHR) on the somatotroph cells of the anterior pituitary. Binding there prompts those cells to synthesize and release growth hormone in pulses, the same rhythm the body uses naturally. The downstream growth hormone then drives the liver to produce IGF-1, which carries out much of GH's metabolic signaling.
There's a built-in brake. The pituitary still answers to somatostatin, the inhibitory hormone that normally damps GH output, so sermorelin's effect runs through that feedback loop rather than around it. This is the mechanistic difference people point to versus injecting recombinant growth hormone, which raises GH directly and can push it past physiological levels. According to DrugBank, sermorelin mimics endogenous GHRH on pituitary receptors to promote pulsatile GH release.
Regulatory history
This is where sermorelin is unusual for a research peptide: it was a real, approved drug.
- The FDA first cleared sermorelin in 1990 as a diagnostic agent, sold as Geref Diagnostic, used to evaluate pituitary GH secretion.
- A second approval came in 1997 under the name Geref, for treating growth hormone deficiency and growth failure in children.
- Manufacturer EMD Serono discontinued the products in 2008, and FDA marketing approval lapsed at the end of the decade.
The reason for the withdrawal matters. In a determination published in the Federal Register on March 4, 2013, the FDA stated that Geref (sermorelin acetate) injection was not withdrawn for reasons of safety or effectiveness. It was a commercial decision. That distinction is why the compound can still be made by compounding pharmacies today.
So the current picture is split. There is no FDA-approved branded sermorelin product on the U.S. market. What exists is compounded sermorelin acetate, prepared by state-licensed compounding pharmacies and 503B outsourcing facilities, plus material sold for laboratory use. The Wikipedia entry summarizes the same approval-and-discontinuation arc.
Anti-doping status
Sermorelin is banned in sport. It sits under Section S2 of the World Anti-Doping Agency Prohibited List, the category for peptide hormones, growth factors, and related substances, alongside the other GHRH analogs such as tesamorelin, CJC-1295, and the GH secretagogues. Both WADA and a reference copy of the S2 list classify GHRH-releasing factors as prohibited at all times.
The quality angle for buyers
Because approved branded sermorelin is gone, anything you encounter outside a clinical setting comes from a compounding pharmacy or a research-chemical supplier, and quality varies. The things worth checking are the same ones that matter for any peptide sold this way:
- Identity and purity on a certificate of analysis (COA), ideally by HPLC and mass spec, confirming it's actually GRF(1-29)NH2 at the stated purity.
- Who issued the COA and whether it's lot-specific rather than a generic document.
- Independent third-party testing, which is the data peptideone aggregates from outside raters rather than relying on a seller's own paperwork.
None of this is medical or dosing advice. Material sold for research is labeled research-use-only and is not approved for human consumption. If GH-axis treatment is the actual question, that's a clinical decision for a licensed prescriber, not something to settle from a product page.