The active 29-amino-acid piece of growth hormone-releasing hormone. FDA-approved for children until its maker stopped selling it in 2008.
Also called Sermorelin acetate, Geref, GHRH(1-29)-NH2, GRF(1-29), GHRH 1-29
Sermorelin is the first 29 amino acids of human growth hormone-releasing hormone (GHRH), the part that does all the signaling. It tells the pituitary to release growth hormone the way your own hypothalamus does. Unlike giving growth hormone directly, it only works if the pituitary works, and the body's normal brakes (somatostatin and IGF-1 feedback) still apply.
It is the one peptide in this family with an FDA approval history. Serono's Geref was approved in 1990 as a diagnostic test of pituitary function and in 1997 to treat children with idiopathic growth hormone deficiency. In the main pediatric study, 30 mcg/kg each night raised height velocity from 4.1 to 8.0 cm a year at 6 months. EMD Serono discontinued both products in 2008, and in 2013 FDA formally determined they were not withdrawn for safety or effectiveness reasons. In a 1993 randomized trial in 60 children, growth was clearly faster on daily growth hormone than on sermorelin given by continuous infusion (14.6 vs about 9.2 cm a year).
Sermorelin's popularity today is in adult anti-aging clinics, and that use has much weaker evidence. Small trials in older men from the 1990s showed it can bring GH and IGF-1 back toward young-adult levels, but changes in muscle, fat and strength were small, inconsistent or absent. No trial has measured long-term outcomes such as fractures, frailty or survival. It is banned in sport by WADA.
What it binds to, and what happens inside the body after that, step by step.
Sermorelin binds the GHRH receptor on somatotroph cells in the anterior pituitary and makes them release growth hormone, which raises IGF-1 from the liver. Because it is cleared in minutes, each injection produces one pulse, and nightly dosing adds to the natural overnight GH surge. Somatostatin and IGF-1 feedback still cap the response, which is the main difference from injecting growth hormone itself.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
In children with idiopathic GH deficiency, nightly sermorelin roughly doubled growth rate in open-label studies, and randomized trials against growth hormone found GH produced faster growth. In healthy older adults, small trials of 10 to 20 people show it raises GH, and IGF-1 with twice-daily dosing, with scattered gains in strength, skin thickness or lean mass and no consistent change in body fat. There are no long-term adult outcome trials.
110 prepubertal children with untreated GH deficiency (86 analyzed for efficacy)
Height velocity rose from 4.1 cm/yr at baseline to 8.0 cm/yr at 6 months and 7.2 cm/yr at 12 months; 74% were good responders.
Read the study60 children with GH deficiency of hypothalamic origin, randomized to sermorelin 30 or 60 mcg/kg/day by continuous infusion or GH, 6 months
Height velocity was 9.2 and 9.3 cm/yr on the two sermorelin doses vs 14.6 cm/yr on GH (p < 0.01); 39 of 40 sermorelin-treated children developed anti-GHRH antibodies.
Read the study10 healthy men aged about 68, compared with 9 young men, randomized order of low and high dose
1 mg twice daily for 14 days raised 24-hour GH and IGF-1 to levels no different from young men; 0.5 mg did not.
Read the study11 healthy men aged 64-76 with low IGF-1, 6 weeks
Nightly 2 mg raised nocturnal GH, but IGF-1, weight, fat and muscle by DEXA did not change; 2 of 6 strength measures improved.
Read the study19 adults aged 55-71 (single-blind, placebo lead-in, then 16 weeks of a close sermorelin analog)
IGF-1 rose within 2 weeks; skin thickness increased in both sexes, while lean mass, insulin sensitivity and libido improved in men only.
Read the study10 healthy men given IV infusions
Native GHRH(1-29) disappeared with a half-time of 4.3 minutes.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
These are questions the published research has not answered.
EMD Serono notified FDA in 2008 that both Geref products were being discontinued; FDA withdrew approval of NDA 19-863 and NDA 20-443 effective June 18, 2009, at the company's request. The March 2013 Federal Register notice allows a generic (ANDA) version to be approved if one is filed. No sermorelin product is currently marketed as an approved drug in the US. Prohibited at all times under WADA S2.2.4 as a GHRH analog.
How much of Sermorelin is left after a single dose
Simple first-order model from the published half-life. Real clearance varies with dose, route, kidney and liver function and formulation. This is not a dosing schedule.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
FDA determined in 2013 that Geref was not withdrawn for safety or effectiveness reasons. EMD Serono discontinued both products in 2008 and asked FDA to withdraw the approvals.
It can restore GH and IGF-1 in older men to young-adult levels for weeks. Body composition and strength changes in those small trials were inconsistent, and no trial has tested aging outcomes.
The feedback brakes are real and limit peak GH. But no trial has compared the long-term safety of sermorelin and GH in adults.
In 6 weeks of nightly use in older men, DEXA muscle and fat did not change. A 16-week analog study found lean mass gains in men only.
It is the same molecule, but no approved product has been sold since 2008, and compounded batches are not tested or approved by FDA.
These pairings come up often. Almost none have been tested together in a trial, and the evidence note on each says so plainly.
Hits the GHRH receptor and the ghrelin receptor at the same time to raise the GH pulse more than either alone.
EvidenceNo clinical trial has tested this combination. FDA's adverse event database includes a report involving a compounded ipamorelin-sermorelin product.
The former Geref label is no longer available as a current FDA document; compounded products carry pharmacy-assigned storage directions, usually refrigeration.
Follow the dispensing pharmacy's beyond-use date. No published stability study covers compounded sermorelin solutions.
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