DOSE-CONTEXT · RESEARCH
Sermorelin dosage as it appears in the studies
The doses and routes administered in published research, with the half-life and stability record — described, never recommended.
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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 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.