Sermorelin is GHRH(1-29), the shortest fully active growth-hormone-releasing fragment, read here through its research record.

The short version

Sermorelin is a lab-made copy of the first 29 building blocks of GHRH — the hypothalamic hormone (a brain signal) that tells the pituitary gland to release growth hormone (GH). Those 29 pieces are the shortest stretch that still does the full job. Instead of injecting GH directly, sermorelin nudges the body to make its own, in its natural pulses. It was once an approved drug for short children, was pulled from the US market in 2008 for business reasons (not safety), and is now made by compounding pharmacies. This page logs what the studies actually measured.

What sermorelin is

Sermorelin (sermorelin acetate) is a synthetic, amidated 29-amino-acid peptide corresponding to the amino-terminal 1-29 fragment of human growth hormone-releasing hormone (GHRH) — the full hormone runs 44 residues, and the 1-29 fragment is the shortest piece that retains full activity at the GHRH receptor ^[1]. Its molecular weight is 3357.9 Da and its CAS number is 86168-78-7. As a pituitary GH secretagogue (a molecule that prompts the pituitary to secrete its own hormone), it acts upstream rather than supplying outside hormone.

The compound has a documented regulatory history that is frequently misstated. Sermorelin was an FDA-approved drug for idiopathic growth-hormone deficiency and short stature in children, and a diagnostic GHRH-stimulation agent. It was withdrawn from the US market in 2008 for commercial reasons — not for any safety or efficacy failure ^[1][2]. It is now prepared by compounding pharmacies and is treated as a long-standing Category 1 bulk drug substance under FDA's interim Section 503A policy (final guidance January 2025). This is a record-grade material framing: described, cited, and not sold here.

Sermorelin as a research peptide: GHRH(1-29)NH2

As a research peptide, sermorelin is the amidated GHRH(1-29) fragment — GHRH(1-29)NH2, also written GRF(1-29)NH2. Amidation (capping the chain's tail end) and the acetate-salt form are part of why the molecule is supplied as a stable lyophilized (freeze-dried) powder rather than a ready-made solution: aqueous peptide solutions degrade, so the dry powder is reconstituted before study use ^[3].

The identity matters because much of what circulates online conflates sermorelin with longer-acting engineered analogs (CJC-1295) or with mechanistically different secretagogues (ipamorelin, a ghrelin-receptor peptide). Sermorelin is the native short-acting GHRH sequence. The sermorelin mechanism of action page traces that receptor pharmacology in full.

Sermorelin acetate: the amidated GHRH(1-29) salt

Sermorelin acetate is the acetate salt of the amidated GHRH(1-29) peptide. In the published pharmacokinetic work, GHRH(1-29)NH2 elicited significant GH release in healthy men at intravenous doses as low as 0.25 mcg/kg, with maximal release at 1-2 mcg/kg ^[3]. The supplied form is a lyophilized powder reconstituted with sterile diluent and typically refrigerated once in solution; compounded preparations are made under USP <797> sterile-compounding standards ^[3].

What the literature has measured

In a multicenter trial of prepubertal GH-deficient children, once-daily subcutaneous GHRH(1-29) accelerated linear growth: first-year height velocity rose from about 4.1 cm/year to roughly 7-8 cm/year, without excessive IGF-1 generation ^[4]. In healthy older men (mean 68 years), GHRH(1-29) at 0.5 mg and 1 mg twice daily for 14 days produced dose-related increases in 24-hour GH and IGF-1; after high-dose treatment, GH/IGF-1 parameters no longer differed from those of young men, with no effect on fasting glucose ^[5].

Those are the confirmed records. Alongside them sit frontier signals from GHRH-agonist analogs — dermal-fibroblast proliferation through ERK/AKT pathways, a cardiac GHRH-receptor repair signal, and an in-silico glioma drug-repurposing flag ^[6][7][8]. These are hypothesis-generating preclinical and computational findings, tagged as such throughout this record, never presented as clinical evidence. The what the research describes page separates the two tiers explicitly. One caution belongs on the front page: anti-aging and body-composition marketing for sermorelin outpaces the rigorous long-term evidence, a point an Annals of Internal Medicine editorial made directly ^[2].

What is sermorelin?

Sermorelin (sermorelin acetate) is a synthetic amidated 29-amino-acid peptide corresponding to the 1-29 N-terminal fragment of growth hormone-releasing hormone (GHRH) — the shortest fragment that retains full GHRH activity ^[1]. It is a pituitary GH secretagogue: it prompts the pituitary to release the body's own growth hormone rather than supplying hormone directly.

What does sermorelin do to the body?

It binds GHRH receptors on pituitary somatotrophs (the GH-producing cells), activating the adenylate cyclase / cAMP / PKA pathway to stimulate the body's own pulsatile GH release and downstream hepatic IGF-1 ^[1]. Because it acts upstream, somatostatin and IGF-1 negative feedback stay intact, preserving the natural pulse pattern.

What is sermorelin used for?

Historically it was an FDA-approved treatment for idiopathic GH deficiency and short stature in children, and a diagnostic GHRH-stimulation agent ^[1][4]. In adult research it has been studied in relation to the aging GH/IGF-1 axis, body composition, cognition, and sleep ^[5][2]. It is not currently marketed as a branded product.

Frontier research: other GHRH-analog applications

A 2025 review surveys GHRH-analog development across cancer, regenerative medicine, and metabolic disorders ^[9]. Separate preclinical work shows GHRH-agonist analogs (MR-409, MR-502) promoting dermal-fibroblast proliferation and wound closure via ERK/AKT ^[6], plus a cardiac-repair signal through GHRH-receptor targeting ^[7]. These are research frontiers, not approved sermorelin uses.