Sermorelin Acetate

Origin and structure

Sermorelin is a synthetic peptide made of the first 29 amino acids of human growth-hormone-releasing hormone (GHRH), with an amide group at the end: 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. Those 29 residues are the shortest part of the natural hormone that keeps its full activity, which is why the fragment is also called GRF(1-29) or GHRH(1-29). It is usually supplied as the acetate salt, sermorelin acetate.

Serono developed it as Geref. In the US it was approved for two uses: a 50-microgram ampoule to test whether the pituitary can release growth hormone (1990), and 0.5 mg and 1 mg vials for children whose growth was failing because of idiopathic growth-hormone deficiency (1997). In Europe the diagnostic Geref 50 was licensed nationally, for example in Ireland from 1991. The Irish licence was withdrawn in 2007, the US products were discontinued in 2008, and no generic version has been approved in the US since.

How it works

Sermorelin binds the GHRH receptor on the growth-hormone-producing cells (somatotrophs) of the anterior pituitary, the same receptor the body's own GHRH uses. The pituitary answers with a burst of growth hormone, and growth hormone in turn raises IGF-1, mainly from the liver. Because it acts one step above growth hormone, the normal brakes still work: somatostatin and rising IGF-1 damp the response, and it only works if the pituitary itself can still make growth hormone. That dependence is what made it useful as a test.

It is short-lived. The Irish Geref 50 label gave a plasma half-life of 6 to 7 minutes after an intravenous injection, with the growth-hormone peak about 30 minutes after the dose and a response lasting 2 to 3 hours. Obesity, high blood sugar and high fatty-acid levels blunt the response. In the trials in older adults, one evening injection produced a single large growth-hormone burst; it did not restore the repeated night-time pulses of young adults, and later in the night growth-hormone output was lower than before treatment.

Is sermorelin approved?

Not any more. It was a prescription medicine in the US, and the diagnostic version was also licensed in Europe, but no sermorelin medicine is on the market in the EU or the US today.

In the Netherlands no sermorelin medicine is registered, so it cannot be prescribed or sold as a medicine. What our shop sells is research material for the laboratory. Research-grade sermorelin is not Geref: it has no marketing authorisation and is not meant for use in people.

In the United States, what clinics prescribe now is made by compounding pharmacies. Compounded preparations are not FDA-approved, which means the FDA has not reviewed their safety, effectiveness or quality.

• US: Geref 0.05 mg (the diagnostic test) was approved on 28 December 1990 and Geref 0.5 mg and 1 mg (idiopathic growth-hormone deficiency in children) on 26 September 1997. EMD Serono told the FDA in July and December 2008 that it was discontinuing them, and both approvals were withdrawn on 18 June 2009.
• US, 2013: in answer to a citizen petition, the FDA determined that neither product had been withdrawn for reasons of safety or effectiveness, which allows generic versions to be approved. None has been; Drugs@FDA still lists only the discontinued Geref products.
• EU: the EMA has never authorised sermorelin. The diagnostic Geref 50 was licensed nationally; the Irish licence, issued on 26 July 1991, was withdrawn on 6 July 2007.
• Sport: prohibited at all times under class S2.2.4 of the WADA Prohibited List, which names sermorelin among the growth-hormone-releasing factors. In the Netherlands the Dopingautoriteit applies the same list.

What the research shows

Sermorelin is unusual among peptides sold for research: it went through clinical development and was approved. But almost all of that work was in diagnostic testing and in children with growth-hormone deficiency, in the 1980s and 1990s. The adult studies are small, short and mostly in people over 60, and none has tested sermorelin for injury recovery, athletic performance or lifespan. The main results:

• Diagnosis (1999 review): a single intravenous dose of 1 µg/kg is a rapid and fairly specific test of the pituitary's growth-hormone reserve, with fewer false positives than other stimulation tests; a normal result cannot rule out deficiency that starts higher up, in the hypothalamus.
• Children with growth-hormone deficiency (Thorner 1996, Geref International Study Group): 110 previously untreated prepubertal children in an open multicentre study without a control group, 86 of them analysed for efficacy. Height velocity rose from 4.1 cm a year to 8.0 after 6 months and 7.2 after 12 months, and 74% counted as good responders at 6 months. Bone age did not run ahead of height, and there was no rise in fasting glucose and no excessive IGF-1.
• Against growth hormone (1999 review): in comparisons, sermorelin given as a continuous infusion or in three daily doses raised height velocity less than daily growth hormone at the same 30 µg/kg. The once-nightly dose was never compared head to head, and its effect on final adult height was never established.
• Older men, two weeks (Corpas 1992): 10 healthy men with a mean age of 68 took 0.5 mg and 1 mg twice daily for 14 days each. Only the higher dose raised 24-hour growth hormone and IGF-1 significantly, to levels no longer different from those of 9 young men.
• Older men, six weeks (Vittone 1997): 11 men aged 64 to 76 injected 2 mg each night. Night-time growth hormone rose but IGF-1 did not; 2 of 6 strength measures and one endurance test improved, and body composition did not change. There was no placebo group.
• Older adults, about six months (University of Washington, placebo-controlled): a nightly injection of about 1 mg raised IGF-1 by roughly 30 to 40% in men and in women not taking oestrogen, but by less than 10% in women on oral oestrogen. Lean mass rose and body fat fell, but strength and aerobic fitness did not improve. In 89 participants, several tests of fluid intelligence improved compared with placebo.
• Younger men (Sigalos 2017): a chart review of men on testosterone at a US clinic who were prescribed sermorelin together with GHRP-2 and GHRP-6. Of 105, only 14 met the compliance criteria; their IGF-1 rose from 159.5 to 239.0 ng/mL over a mean of 134 days. There was no control group, and the share of sermorelin cannot be separated from that of the other two peptides.

Sermorelin versus growth hormone

Sermorelin is often presented as a gentler alternative to growth hormone because it makes the body release its own. That part holds up: it needs a working pituitary, the normal feedback through somatostatin and IGF-1 stays in place, and a 2008 review of GHRH in ageing described its side effects as similar in kind to those of growth hormone but milder and less frequent.

The other side is a smaller and less predictable effect. In children it raised growth rate less than growth hormone did, and in adults the response depends on the pituitary, falls sharply with oral oestrogen and is blunted by obesity and high blood sugar. Most adults with proven growth-hormone deficiency have pituitary damage and respond poorly to GHRH, so there are few studies of sermorelin in that group; growth hormone itself is an approved treatment for them, while no regulator has approved a growth-hormone secretagogue for normal ageing.

Side effects and warnings

The label and trial data describe a mild profile. The most commonly reported effects were facial flushing or a feeling of warmth and pain at the injection site, which according to the Irish label usually passed within minutes. In the children's trial no adverse changes in blood chemistry or hormone tests were seen. In the older-adult trials the typical growth-hormone side effects, swelling from fluid retention and joint pain, were very uncommon, and redness or swelling at the injection site was reported only rarely.

The diagnostic label excluded pregnancy and breastfeeding and asked for particular caution in people with diabetes or epilepsy. Beyond that the record is thin: the longest adult studies ran about six months, so the effects of keeping IGF-1 raised for years are unknown. These data come from Geref, a licensed medicine; they say nothing about the content of unlicensed products.

Frequently asked questions

Is sermorelin the same as growth hormone (HGH)?

No. Growth hormone is the hormone itself; sermorelin is a short signal peptide that asks the pituitary to release its own. It only works if the pituitary can respond, its effect is smaller and more variable, and in children it raised growth less than growth hormone did.

Why was Geref taken off the market?

EMD Serono discontinued the US products in 2008, and the approvals ended in June 2009. The company's reason is not in the FDA record, but in 2013 the FDA formally determined that Geref had not been withdrawn for reasons of safety or effectiveness, which leaves the way open for a generic version. None has been approved.

Is sermorelin legal in the Netherlands?

There is no registered sermorelin medicine in the Netherlands, so it cannot be prescribed or sold as a medicine. It is available as research material for laboratory use, not for use in people. For athletes a separate rule applies: it is on the doping list.

Is sermorelin banned in sport?

Yes, at all times, in and out of competition. The WADA Prohibited List names sermorelin in class S2.2.4 among the growth-hormone-releasing factors, and the Dopingautoriteit applies that list in the Netherlands.

Does sermorelin improve sleep?

Not in the trial that tested it. In the placebo-controlled University of Washington study, months of nightly sermorelin did not improve deep sleep, and in an interim analysis self-rated sleep quality became slightly worse (Pittsburgh score from 4.1 to 5.4 in 37 people) while it stayed the same on placebo.

Does sermorelin build muscle?

In older adults, about six months of nightly sermorelin increased lean mass and lowered body-fat percentage by about 5%, but strength and aerobic fitness did not improve compared with placebo. There are no trials in younger adults or athletes.

Storage and handling

Store according to product-label instructions and batch handling notes. Lyophilized research peptides are commonly kept dry, protected from light, and handled with clean laboratory technique.

References

Checked against these sources on 28 October 2026.

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