Sermorelin

What it is

Sermorelin is a synthetic peptide made of the first 29 amino acids of natural growth hormone-releasing hormone (GHRH), the shortest fragment that keeps the full biological activity of the parent hormone [4][5]. It was sold in the United States as Geref by EMD Serono under two approvals: a 0.05 mg ampoule approved December 28, 1990 for testing whether the pituitary can secrete growth hormone, and 0.5 mg and 1.0 mg vials approved September 26, 1997 for treating idiopathic growth hormone deficiency in children with growth failure [1]. Both products were discontinued by the company in 2008 and the approvals were withdrawn in 2009 [1]. Today sermorelin reaches patients only as a compounded preparation, most often for adults, a use that the former approvals did not cover [8].

How it works

Sermorelin binds the GHRH receptor on somatotroph cells in the anterior pituitary and stimulates them to release growth hormone (GH), which then raises insulin-like growth factor I [4][5]. Given intravenously or subcutaneously it specifically stimulates GH secretion, without meaningful effects on other pituitary hormones [5]. The pituitary response is quick: after a single dose, the peak GH response arrives at roughly 30 minutes (range 15 to 60) and lasts two to three hours, well beyond the time the peptide itself remains in the blood [4]. Because it works through the pituitary, sermorelin depends on an intact hypothalamic-pituitary axis; conditions such as obesity, high blood glucose and elevated plasma fatty acids are associated with poor GH responses, and untreated hypothyroidism or high somatostatin levels can blunt the response [4].

What the evidence shows

The clinical evidence for sermorelin comes from its use as a diagnostic test and from small pediatric treatment studies. As a test, a single intravenous dose produced fewer false-positive GH responses in children without GH deficiency than other provocative tests, but a normal response cannot exclude GH deficiency of hypothalamic origin [5]. As a treatment, limited data showed significant increases in height velocity sustained over 12 months in some prepubertal children with idiopathic GH deficiency, with a few children followed to 36 months; the effect on final adult height was not determined [5]. In comparisons, height-velocity gains with sermorelin were smaller than with once-daily somatropin [5]. No fetched source reports controlled trials of sermorelin in adults for body composition, sleep, aging or recovery.

Regulatory status

Sermorelin is not an FDA-approved drug today. FDA withdrew approval of NDA 019863 and NDA 020443 effective June 18, 2009 after EMD Serono discontinued both Geref products and requested withdrawal [1]. In a March 4, 2013 Federal Register notice, FDA determined the products were not withdrawn for reasons of safety or effectiveness, which would allow generic applications if anyone filed one [1]; Drugs@FDA lists both applications as discontinued [2][3]. Sermorelin does not appear in Category 1, 2 or 3 of the 503A nominated list FDA updated May 14, 2026 [6]. Sermorelin acetate is in Category 1 of the 503B nominated list updated March 21, 2025, marked as a component of an FDA-approved drug [7]. FDA’s October 2024 briefing describes compounded ipamorelin and sermorelin combinations being marketed [8]. Verified September 24, 2026.

Half-life and what it means for a level curve

The reference half-life in STACK is 0.11 hours. That is 6 to 7 minutes, the plasma half-life after intravenous administration stated in the Irish Geref 50 product information; the same document notes the GH response peaks about 30 minutes after a dose and lasts two to three hours [4]. No fetched primary source gives a subcutaneous half-life, and the withdrawn US label is not available as text, so the intravenous value is used. In practice a half-life of minutes means the estimated level rises and vanishes within about an hour of each injection: five half-lives, the point at which a level reaches about 97 percent of steady state, is only about 35 minutes here, so there is no build-up between daily doses. The curve is really a marker of when you injected. STACK’s curve is an estimate from this published half-life, not a blood level.

Reported side effects

In the approved-era literature, single intravenous doses and repeated once-daily subcutaneous doses were described as well tolerated; transient facial flushing and pain at the injection site were the most commonly reported adverse events [5]. The Irish product information lists facial heat, facial flush and injection-site pain that usually disappear within a few minutes, and states the product is contraindicated in known hypersensitivity and in pregnancy or lactation [4]. It also advises particular caution in people with diabetes or epilepsy [4]. These data come from short diagnostic use and from children treated for GH deficiency, not from long-term adult use. FDA’s 2024 review found adverse event reports involving compounded products containing sermorelin with ipamorelin but could not attribute them to either peptide [8].

Storage and handling

The Irish Geref 50 product information says to store the powder at 2 °C to 8 °C, protect it from light, reconstitute immediately before use with the solvent provided and discard any product left after use [4]. Compounded sermorelin in the United States has no FDA label, so your pharmacy’s label governs: follow its instructions on refrigeration, light protection, the beyond-use date and how long a reconstituted vial may be kept, which may differ from the single-use ampoule described above. STACK’s reconstitution calculator does the volume arithmetic from the concentration and diluent volume on your vial; it does not suggest what to take. If the solution is discoloured or past its pharmacy date, ask the pharmacy before using it.

What STACK tracks for it

STACK logs each sermorelin dose as your prescriber wrote it, in mcg, with the date, time and injection site, and draws an estimated level curve from the 0.11-hour reference half-life, which you can replace with your own estimate. Because the curve collapses within an hour, its main use is as a timing record: you can see at a glance whether you injected at the time your prescriber suggested and how consistent you have been. You can also log sleep, weight, injection-site reactions and any side effect, and keep a vial inventory with the pharmacy’s beyond-use date. If sermorelin is dispensed in a combination vial with ipamorelin, log it under the compound name on the label and note the combination. STACK shows; it never prescribes.

The reference half-life in STACK

STACK's simulator and the app use 6.6 min for Sermorelin: 6–7 minutes after intravenous injection; no subcutaneous value in a fetched primary source. Measured in: adults, intravenous administration (Geref 50 Summary of Product Characteristics, Irish Medicines Board).

Estimate only. Modelled from the published half-life you selected and the doses you logged — not a measured blood level. Do not use it to make medication decisions.

Free tools for Sermorelin

Read next

Sources

Every URL below was fetched and checked on 2026-09-24. Bracketed numbers in the text link here.

1. FDADetermination That GEREF (Sermorelin Acetate) Injection Was Not Withdrawn From Sale for Reasons of Safety or Effectiveness — Federal Register, March 4, 2013
2. FDADrugs@FDA: NDA 020443 GEREF (sermorelin acetate)
3. FDADrugs@FDA: NDA 019863 GEREF (sermorelin acetate)
4. LabelGeref 50 (sermorelin acetate) Summary of Product Characteristics — Irish Medicines Board (HPRA)
5. ReviewSermorelin: a review of its use in the diagnosis and treatment of children with idiopathic growth hormone deficiency (Prakash & Goa, BioDrugs 1999)
6. FDABulk Drug Substances Nominated for Use in Compounding Under Section 503A, updated May 14, 2026 — FDA
7. FDABulk Drug Substances Nominated for Use in Compounding Under Section 503B, updated March 21, 2025 — FDA
8. FDAFDA Briefing Document, Pharmacy Compounding Advisory Committee, October 29, 2024 (ipamorelin-related bulk drug substances)