Sermorelin is the first 29 amino acids of human growth hormone releasing hormone (GHRH), the hypothalamic hormone that tells the pituitary to release growth hormone. The full hormone is 44 amino acids long, but when it was first isolated in 1982 from a pancreatic tumour that had caused acromegaly, the 1-29 fragment turned out to carry all of its activity. That fragment is sermorelin. Unlike growth hormone itself, it does nothing without a working pituitary, and the pituitary keeps its own feedback controls in place, which is the main argument its developers made for it. It was approved in the United States under the brand name Geref, first as a diagnostic agent and then, in 1997, for treating growth hormone deficiency in children.

SermorelinWhat the studies show

Q: What kind of evidence exists for sermorelin?

Large human trials. Clinical trials in growth-hormone-deficient children that supported FDA approval, plus small, short hormone studies in healthy older men; well-characterised for its approved use, and untested for the uses adults usually ask about.

The first 29 amino acids of GHRH, once an FDA-approved drug for children who do not make enough growth hormone, and withdrawn from the market in 2008.

5 min read · Large human trials · Updated November 2026

In short

Name: sermorelin
Evidence: Large human trials
Bottom line: Clinical trials in growth-hormone-deficient children that supported FDA approval, plus small, short hormone studies in healthy older men; well-characterised for its approved use, and untested for the uses adults usually ask about.

Before you read this

This guide explains what published studies found. That is all it is.

It is not medical advice and it is not instructions for using anything. Where a dose appears, we are reporting what a named study gave the people or animals in it — a fact about the study, not an instruction to you.

The compounds here are not approved by the FDA for use in people and are sold for laboratory research only. A study tells you what happened to the subjects in it; it does not tell you what would happen to you. Talk to a doctor first.

What it is

Sermorelin is the first 29 amino acids of human growth hormone releasing hormone (GHRH), the hypothalamic hormone that tells the pituitary to release growth hormone. The full hormone is 44 amino acids long, but when it was first isolated in 1982 from a pancreatic tumour that had caused acromegaly, the 1-29 fragment turned out to carry all of its activity ¹. That fragment is sermorelin. Unlike growth hormone itself, it does nothing without a working pituitary, and the pituitary keeps its own feedback controls in place, which is the main argument its developers made for it ². It was approved in the United States under the brand name Geref, first as a diagnostic agent and then, in 1997, for treating growth hormone deficiency in children ².

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Children with growth hormone deficiency

The approval rested on growth. In a 1996 study in the Journal of Clinical Endocrinology & Metabolism, prepubertal children with growth hormone deficiency were given sermorelin under the skin once a day, and their height velocity over the first year of treatment was compared with the year before it; they grew faster on treatment ³. A 1999 review of the clinical programme summarised the diagnostic and treatment trials and put sermorelin's half-life in the blood at a matter of minutes, which is why it was given daily and why its effect depends on the pituitary's own response rather than on a steady level of drug ². Because it works only through the child's own pituitary, the response depends on how much growth hormone that pituitary can still make, which is why the approved use was for children whose deficiency arose above the pituitary rather than in it ².

Older men

Growth hormone output falls with age, and sermorelin was studied as a way to see whether the ageing pituitary still responds. In a 1992 study from the National Institute on Aging, healthy men over 60 were given sermorelin twice a day for two weeks, and their growth hormone and IGF-1 levels, low at the start, rose into the range seen in young men ⁴. A 1997 study gave healthy elderly men a single injection each night for several weeks and likewise found raised night-time growth hormone and IGF-1 ⁵. Both were small and short, and both measured hormones; neither was designed to show a change in how the men looked, felt or performed. Whether the restored hormone levels would translate into anything measurable over months was exactly what these studies were too short to ask, and the question has not been answered since.

Geref, and why it is gone

Serono marketed Geref in the United States for about a decade. In 2008 it was discontinued, and the FDA later published a determination that the product had not been withdrawn from sale for reasons of safety or effectiveness, the finding that allows generic versions to be considered ⁶. No branded sermorelin product has returned to the U.S. market since; what circulates under the name today is compounded or research material, not the approved drug, and the trials above were done with the approved one.

What is not known

Sermorelin's evidence is for children with growth hormone deficiency and for hormone levels in older men over weeks. There is no large trial of sermorelin in healthy adults for body composition, sleep, recovery or ageing, and no long-term outcome data in anyone. The feedback-safety argument for it is physiological reasoning supported by short studies, not a tested long-term claim.

What these studies are, and aren't

Large human trials. Clinical trials in growth-hormone-deficient children that supported FDA approval, plus small, short hormone studies in healthy older men; well-characterised for its approved use, and untested for the uses adults usually ask about.