What it is
Sermorelin is a peptide made of 29 amino acids. It is made in a lab. It copies the first 29 amino acids of growth hormone releasing hormone, or GHRH. Natural GHRH has 44 amino acids. These first 29 are the shortest piece that still works fully at the GHRH receptor. GHRH is the signal the brain sends to the pituitary gland to release growth hormone. The FDA approved sermorelin under the brand name Geref to test and treat growth hormone deficiency in children. The maker stopped selling it around 2008 for business reasons, not safety reasons. CJC-1295 is a later version of the same 29 amino acids with four of them swapped. Other names: Geref, GRF 1-29, GHRH(1-29)NH2.
What researchers study it for
- Growth hormone levels in older adults
- IGF-1 levels and body makeup in older adults
- Growth hormone deficiency in children
- Whether the aging pituitary gland can still respond to GHRH
- How it compares to longer-lasting GHRH peptides like CJC-1295
What the studies found
1. Nightly shots raised growth hormone at night in older men. IGF-1 and body fat did not change.
A 1997 study gave 11 healthy men, ages 64 to 76, a sermorelin shot every night for 6 weeks. Growth hormone released during the night went up. IGF-1, the growth signal the liver makes, did not change. Body weight, muscle, and fat measured by body scan did not change. Two of six strength tests improved, and the authors concluded that one shot a night works less well than several shots a day.
2. The pituitary gland of older men still responded to GHRH.
This 1993 study used the full 44 amino acid GHRH, not sermorelin. Men ages 64 to 76 got it through a small pump under the skin for 14 days. Their 24-hour growth hormone and IGF-1 levels went up. This showed the drop in growth hormone with age comes mostly from a weaker GHRH signal, not a worn-out pituitary gland. The steady pump also made the normal night peaks smaller, which is why later research moved to short bursts instead.
3. It works through the body's own brake system.
This 2006 paper is an opinion piece, not a new trial. The author points out that growth hormone shots skip the pituitary gland. Sermorelin makes the pituitary release its own growth hormone. That release is still controlled by somatostatin, the hormone that shuts growth hormone off. The paper argues this makes it hard to push growth hormone too high.
How much research exists
It has more human data than any other GHRH peptide because it was once an approved drug. Most of that data comes from small studies in older adults and from the children's approval trials, many from the 1990s. Few new trials have been run since it left the market.
Facts
- Formula: C149H246N44O42S
- Weight: 3357.9 g/mol
- CAS number: 86168-78-7
- Sequence: Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-NH2
- Time in the blood: 10 to 20 minutes
- Storage: freeze the dry powder. Keep mixed solution in the fridge.
Legal status
Once approved by the FDA as Geref. The maker stopped selling it around 2008, and the approval was withdrawn in 2009. The FDA stated neither step was for safety reasons. No FDA-approved sermorelin product is sold in the United States today. Banned in sports by WADA under section S2.
For research use only. Not for human use. Nothing here is medical advice.