# Sermorelin: The GHRH(1-29) Growth Hormone Secretagogue, Decoded > Sermorelin is the GHRH(1-29) growth hormone secretagogue: a synthetic 29-amino-acid peptide, once FDA-approved and withdrawn in 2008 for commercial reasons, now compounded. A cited digest. A spare, cited readout of the mechanism, the pediatric and aging trials, and the full regulatory state machine — approved, withdrawn for commercial reasons in 2008, Category 1 under 503A. ## The short version Sermorelin is a small peptide that tells the pituitary — the gland under the brain — to release the body's own growth hormone, instead of injecting growth hormone directly. It is the first 29 building blocks of GHRH (the brain's own "make growth hormone" signal), so it is called a secretagogue (something that tells a gland to release its hormone). It was once a US-approved prescription drug for children who did not make enough growth hormone, pulled from the market in 2008 for business reasons (not safety), and is now prepared by compounding pharmacies. This site summarizes the published research; it does not sell anything and gives no dosing instructions. ## What sermorelin is Sermorelin (sermorelin acetate, GHRH(1-29)NH2) is a synthetic 29-amino-acid peptide. It reproduces the first 29 residues of the 44-residue hypothalamic hormone GHRH — growth hormone-releasing hormone — and it is the shortest fragment of GHRH that keeps full activity at the GHRH receptor. Its molecular weight is 3357.9 Da and its CAS number is 86168-78-7. The classification matters because people reach for the wrong word. Sermorelin is a growth hormone secretagogue (a substance that prompts a gland to secrete its hormone), specifically a GHRH analog. It is not a controlled substance, and it is not exogenous growth hormone. It was a US-approved finished drug for pediatric growth hormone deficiency, withdrawn from the US market in 2008 for commercial reasons rather than safety or efficacy, and it is now prepared by compounding pharmacies and treated as a long-standing Category 1 bulk drug substance under FDA's interim Section 503A policy (final guidance January 2025) [13]. The full [sermorelin FDA approval status](/regulatory-status) — branded approval, withdrawal, and current 503A footing — is set out as a state machine on its own page. The related GHRH analog tesamorelin (a stabilized version studied alongside GHRH(1-29) in body-composition and cognition research) is FDA-approved for HIV-associated lipodystrophy; CJC-1295 is a longer-acting GHRH analog built on the same axis. Sermorelin is the native short fragment those later analogs iterated on. ## What the research has examined Across the literature, sermorelin and GHRH(1-29) have been examined in three settings the studies actually measured. In its historical approved indication, once-daily subcutaneous GHRH(1-29) accelerated linear growth in growth hormone-deficient children: first-year height velocity rose from about 4.1 cm/year to roughly 7-8 cm/year, without excessive IGF-1 (a growth signal the liver makes when growth hormone rises) generation [1]. In healthy older men (mean 68 years), GHRH(1-29) at 0.5 mg and 1 mg subcutaneously twice daily for 14 days produced dose-related increases in 24-hour growth hormone and IGF-1; after the high dose, those parameters no longer differed from young men, with no change in fasting glucose [2]. In a randomized, double-blind, placebo-controlled trial of 152 older adults, 20 weeks of a daily GHRH analog had a favorable effect on cognition (P=0.03) and raised IGF-1 by 117% within the physiologic range [6]. These are findings, not endorsements. The sermorelin [benefits](/research#what-examined) reported in the literature are GH-axis effects measured under study conditions — not a promise of outcomes in any individual, and not a recommendation. The same literature carries a clear caution: an Annals of Internal Medicine editorial judged growth hormone secretagogue use for aging "not yet ready for prime time" [5]. ## How does sermorelin work to stimulate growth hormone production? Sermorelin is the 1-29 N-terminal fragment of GHRH and binds GHRH receptors on anterior-pituitary somatotrophs (the growth hormone-producing cells), activating adenylate cyclase / cAMP / PKA signaling to stimulate the pituitary's own pulsatile growth hormone release [8]. Because it acts upstream on the pituitary rather than supplying exogenous hormone, somatostatin and IGF-1 negative feedback stay intact, preserving the natural pulsatile (released in natural bursts, not a steady drip) pattern. The full [mechanism at the GHRH receptor](/research#mechanism) is covered on the research page. ## What does sermorelin do to the body? By acting on the pituitary instead of supplying growth hormone directly, sermorelin stimulates the body's own pulsatile growth hormone release and the downstream liver production of IGF-1, while somatostatin and IGF-1 negative feedback remain operative [10]. The intact feedback loop is the structural argument made for the secretagogue approach: an editorial framed sermorelin as a possibly more physiologic option for adult-onset growth hormone insufficiency than recombinant growth hormone [4]. ## What is sermorelin used for? Its historical FDA-approved indication was the evaluation and treatment of growth hormone deficiency / short stature in children, where once-daily subcutaneous dosing accelerated first-year height velocity [1]. In research, GHRH(1-29) and its stabilized analogs have also been studied in adult GH-axis aging, cognition, sleep, and body composition [6], with the related analog tesamorelin studied for HIV-associated fat accumulation. This describes documented study and approval history, not a current treatment recommendation. ## What is sermorelin? Sermorelin (sermorelin acetate, GHRH(1-29)NH2) is a synthetic 29-amino-acid analog of growth hormone-releasing hormone — the shortest GHRH fragment that retains full activity at the GHRH receptor — and a pituitary growth hormone secretagogue [9]. It mimics endogenous hypothalamic GHRH, whose GH-driving signal declines with age. --- A pixel-console readout of the sermorelin record — the GHRH(1-29) mechanism and the trial figures logged to source, and the regulatory state machine (approved, withdrawn in 2008 for commercial reasons, Category 1 under 503A) read exactly as filed; no clinic behind the screen and nothing here compounded, dosed, or sold.