# Sermorelin Dosage in the Research: Routes, Doses Studied, Half-Life > Sermorelin dosage as it appears in the published research — the doses and routes administered in studies, the short half-life, and stability notes. Research context only, no human dosing advice. The doses and routes administered in published research, with the half-life and stability record — described, never recommended. ## Read this first This page describes the **sermorelin dosage** figures that appear in published studies — what was given, to whom, by which route. It is a research record, not guidance. It contains no recommended human dose, no titration schedule, and no "how much to take." Sermorelin is supplied as a lyophilized (freeze-dried) powder that is reconstituted with sterile diluent and refrigerated, because peptide solutions degrade over time [3]. The one practical fact worth carrying away is about timing and route, not amount: sermorelin has a very short half-life and is studied almost entirely by injection, because it is poorly absorbed by mouth or nose [3]. Everything below is attributed to a specific study, and nothing here should be read as a personal protocol. ## Sermorelin dosage: doses and routes in the published studies In the pediatric efficacy study, growth-hormone-deficient children received 30 mcg/kg/day subcutaneously at bedtime [1]. In aging research, healthy older men received 0.5 mg and 1 mg subcutaneously twice daily for 14 days, which produced dose-related GH/IGF-1 increases [2]. In pharmacokinetic work, intravenous doses of 0.25-2 mcg/kg elicited GH release in healthy men, with maximal release at 1-2 mcg/kg [3]. Historically, a single intravenous bolus (commonly around 1 mcg/kg) was used diagnostically to test the pituitary's GH reserve. These figures are reported as what researchers administered under study conditions — they are not a dosing recommendation. The bedtime timing in studies reflects the body's natural tendency to release growth hormone during early, deep sleep, not a rule for any individual. ## Half-life, routes, and why injection dominates the research Sermorelin's plasma half-life is short — roughly 10-12 minutes after intravenous administration — yet a single dose elevates serum GH for about 3 hours [3]. The routes studied are subcutaneous injection (the primary route), intravenous (for diagnostic and pharmacokinetic work), and intranasal (a historical pharmacokinetic study that found bioavailability of only ~3-5%) [3]. That ~3-5% intranasal figure is the mechanistic reason peptides like GHRH(1-29) are not effectively delivered across mucosa, and it underlies the skepticism about oral, sublingual, and troche products covered on the [sermorelin tablets](/tablets) page. The brevity of the native peptide is also why stabilized, longer-acting analogs (D-Ala2 substitution, DAC albumin-binding technology) were developed [3]. Reconstituted, lyophilized sermorelin acetate is typically refrigerated, and compounded preparations are made under USP <797> sterile-compounding standards [9]. ## The diagnostic-test history behind the dose figures Some of the dose numbers in the literature come not from treatment but from diagnosis. Before its withdrawal, GHRH was given as a single intravenous bolus — commonly around 1 mcg/kg — to test how much growth hormone the pituitary could release on demand, a procedure called a GH stimulation test [3]. The pharmacokinetic study that mapped the 0.25-2 mcg/kg dose-response did so to characterize exactly this stimulus-and-response behavior in healthy men [3]. That diagnostic role is part of why the 2008 withdrawal mattered clinically: a 2009 clinical review noted that the resulting absence of commercially available recombinant GHRH in the US pushed clinicians toward alternative stimulation tests for diagnosing adult GH deficiency [8]. So a reader scanning "sermorelin dosage" figures should know that several of them describe a one-time diagnostic challenge, not a repeated treatment regimen — different purpose, different numbers, and neither one a personal protocol. ## Why the short half-life drove the next generation of analogs The single most consequential pharmacokinetic fact about sermorelin is how briefly it lasts. Because GHRH(1-29) clears in minutes, a treatment built on it requires frequent dosing to sustain an effect — and that practical limitation is what motivated chemists to engineer longer-acting relatives [3]. Two strategies appear repeatedly in the literature: substituting a D-amino acid at position 2 (the D-Ala2 modification) to resist enzymatic breakdown, and attaching a Drug Affinity Complex (DAC) — a group that binds the blood protein albumin — to extend circulation to multiple days [3]. The 2025 Nature Reviews Endocrinology synthesis places sermorelin within this broader GHRH-analog landscape, where agonists and antagonists have been developed across endocrine and metabolic research [6]. None of this changes the dosing guidance here, which remains: this page describes what was administered in studies, and recommends nothing. --- A status-and-access ledger of the sermorelin (GHRH 1-29) record — the former approval, the 2008 commercial withdrawal, the Category 1 503A standing and the WADA S2 line each logged to source and kept distinct; no clinic behind the console, no script filled here, nothing dispensed, sourced, or sold.