Sermorelin

A copy of the active first 29 amino acids of the body's own growth-hormone-releasing hormone (GHRH), the shortest fully active fragment. It was once the FDA-approved drug Geref for testing and treating children with GH deficiency; CJC-1295 is built on the same backbone.

Binds GHRH receptors on pituitary cells, which then make and release growth hormone, which raises IGF-1. The body's normal feedback through somatostatin and IGF-1 stays intact, so GH release keeps a pulsed rhythm. It has no stabilizing substitutions, so it is broken down quickly, and it needs working GH-producing cells to have an effect.

About 350 children with GH deficiency were studied in the trials that supported its 1997 approval. In healthy older men, a 1992 NIA study found GH and IGF-1 rose to young-adult levels over two weeks. Two 6-month University of Washington trials in older adults found higher IGF-1, more lean mass and about 5–8% less body fat, with mixed function results; the authors concluded the data do not support routine use in normal aging. There are no large adult trials and no comparison with growth hormone.

On the former label, injection-site pain, redness or swelling affected about 1 in 6 patients, with headache, flushing, dizziness and hives under 1%. Many children developed antibodies that did not affect growth, hypothyroidism appeared in 6.5% during trials, and fluid retention was seen in aging studies. Long-term effects of raised IGF-1 (cancer, glucose) are an open question.

The brand drug Geref was FDA-approved (diagnostic 1990, treatment 1997); the maker discontinued it in 2008, and FDA confirmed in 2013 that withdrawal was not for safety or effectiveness reasons. 503A pharmacies compound it on prescription; it is not on FDA's category or safety-risk lists. WADA prohibits it at all times under S2.2.4 (GHRH and analogs).