Sermorelin is the GHRH(1-29) fragment that charts a route from the pituitary to IGF-1.

The short version

Sermorelin is a small synthetic peptide — 29 amino acids — that copies the front end of a natural brain hormone called GHRH (growth hormone-releasing hormone, the hypothalamus's "make growth hormone" signal). It does not add growth hormone to the body. Instead it knocks on the pituitary gland and asks it to release its own, in the natural bursts the body already uses. Studied since the 1980s, sermorelin was once an FDA-approved children's medicine, was pulled from the US market in 2008 for business reasons (not safety), and is now made by compounding pharmacies. This site maps what the published research actually measured.

Sermorelin Peptide: A GHRH(1-29) Fragment Explained

Sermorelin is the amidated GHRH(1-29) fragment — the first 29 amino acids of the body's own 44-amino-acid growth hormone-releasing hormone, and the shortest piece of that hormone that still does the full job at its receptor ^[3]. Where the full hormone is the entire message, GHRH(1-29) is the part the pituitary actually reads. It corresponds to the amino-terminal stretch of the hypothalamic peptide, carries a molecular weight of 3357.9 Da, and is catalogued under CAS 86168-78-7.

That compactness is the whole engineering story. A 29-residue peptide is easier to synthesize than a 44-residue one and still binds the GHRH receptor with full activity. The trade-off is duration: the native fragment clears from plasma in minutes, which is the central fact of its sermorelin half-life and pharmacokinetics and the reason longer-acting analogs were later built around it.

Sermorelin acts upstream. It does not supply growth hormone the way an injection of the hormone itself would; it prompts the gland that makes growth hormone to release more of its own. Because the signal enters the system at the top, the body's own brakes — somatostatin and IGF-1 feedback — stay in place ^[4]. The sermorelin mechanism of action page charts that route stop by stop.

Sermorelin Acetate: The Lyophilized Research Form

Sermorelin acetate is the salt form used in pharmacology and in compounded preparations — the GHRH(1-29) fragment paired with acetate, supplied as a lyophilized (freeze-dried) powder. The freeze-drying is not decoration: peptides dissolved in water are prone to degradation, so the dry powder is reconstituted with a sterile diluent only when needed, and once reconstituted it is typically refrigerated ^[3]. Compounded preparations are made under USP <797> sterile-compounding standards. The molecular formula is C149H246N44O42S; the parent fragment is GHRH(1-29)NH2, amidated at its end.

This is the form behind almost every figure on this site. When a study reports "GHRH(1-29)" or "sermorelin," it is describing this peptide, delivered by injection. The sermorelin dosage in the literature page collects the routes and research doses on record, framed strictly as how studies were conducted — not as instructions for any individual.

What the Sermorelin record actually shows

In its historical approved use, sermorelin worked. In a multicenter trial of prepubertal growth-hormone-deficient children, once-daily subcutaneous GHRH(1-29) raised first-year height velocity from about 4.1 cm/year to roughly 7-8 cm/year, without excessive IGF-1 generation ^[1]. In healthy older men (mean age 68), 0.5 mg and 1 mg twice daily for 14 days produced dose-related increases in 24-hour growth hormone and IGF-1; after the high dose, their GH/IGF-1 parameters no longer differed from those of young men, with no change in fasting glucose ^[2].

The acute pharmacology is just as concrete. In 30 healthy men, intravenous GHRH(1-29) elicited measurable growth hormone release at doses as low as 0.25 mcg/kg, with maximal release at 1-2 mcg/kg; despite rapid clearance, serum GH stayed elevated for about 3 hours, while intranasal delivery managed only 3-5% bioavailability ^[3].

The honest limits are charted too. The strongest adult body-composition and cognition signals in the audited literature come from a stabilized GHRH analog (tesamorelin), not from native sermorelin ^[6], and a 2008 Annals of Internal Medicine editorial judged growth-hormone-secretagogue use for aging "not yet ready for prime time" ^[5]. The sermorelin benefits reported in research and the safety record are laid out in full on the research page, and the open frequently asked questions about sermorelin collect the rest.

Sermorelin's provenance: formerly approved, now compounded

Sermorelin's history is often misstated, so this site states it plainly. It was FDA-approved (NDA 020443) for the evaluation and treatment of growth hormone deficiency and short stature in children. It was withdrawn from the US market in 2008 for commercial reasons — not because of any safety or efficacy problem ^[5]. It was never a banned or dangerous drug; it simply stopped being sold as a branded product.

Today sermorelin is prepared by compounding pharmacies and is treated as a long-standing Category 1 bulk drug substance under FDA's interim Section 503A policy, with final guidance issued in January 2025. That status is distinct from other growth-hormone-axis peptides reviewed separately by regulators, and should not be conflated with them. This is editorial framing of a documented past — not a claim that sermorelin is currently a prescribable branded medicine, and not a storefront. The route this site charts is through the evidence, not toward a shelf.