Sermorelin
Not FDA-approved
Formerly approved in the US as Geref, for testing pituitary growth hormone release and for growth hormone deficiency in children. Both products were discontinued in 2008.
Also known as: Geref, GHRH(1-29)-NH2
Sermorelin is a lab-made copy of the first 29 amino acids of growth-hormone-releasing hormone (GHRH), the shortest piece with the full hormone's activity. It prompts the pituitary gland to release the body's own growth hormone. In children with growth hormone deficiency it sped growth, though less reliably than growth hormone itself; evidence in healthy adults is thin.
How it works
- It matches the first 29 of the 44 amino acids in natural GHRH, the shortest piece that keeps the hormone's full activity.
- It acts on the pituitary gland to trigger the release of growth hormone, which in turn raises IGF-1.
- It only works if the pituitary can still make growth hormone.
- It is cleared within minutes. In healthy men given it into a vein, half was gone in about four minutes.
Evidence
Growth in children with growth hormone deficiency
An open study of 110 children had no comparison group. In the 86 analysed, growth sped up from 4.1 to 8.0 cm a year at six months. It was 7.2 cm a year at 12 months. Its effect on final adult height was not established.
Compared with growth hormone in children
Two small randomized trials compared it with growth hormone in children whose deficiency began in the hypothalamus, part of the brain. In one, children grew more slowly on sermorelin. In the other, only the higher-dose sermorelin group kept pace, and only growth hormone improved height relative to bone age.
Muscle, fat and aging in healthy older men
In a small study of 11 healthy older men with no placebo group, six weeks of once-nightly treatment raised night-time growth hormone but not IGF-1. Lean mass, fat mass, weight, blood sugar and blood fats did not change; two of six strength tests improved. A 2003 review of this drug class found lean-mass gains after months of treatment. It judged the results not yet enough for routine use in normal aging.
Caveats
- Brief facial flushing and pain at the injection site were the most common side effects.
- Almost all children given it by continuous infusion for six months formed antibodies to it. These faded after stopping and were not linked to how well the children grew.
- Studies in children over a year and in older men found no change in blood sugar.
- Long-term risks in adults are unknown. By extension from growth hormone itself, possible risks include tumor growth, diabetes, fluid retention and raised pressure in the skull.
- No study has measured effects on longevity or other hard outcomes.
References
This page is for education only. It is not medical advice. Decisions about any treatment belong with a physician who knows your history.