# Sermorelin Dosage in the Research Literature — GHRH(1-29) Doses & Half-Life > Sermorelin dosage as documented in studies: the doses, routes, and ~10-12 minute half-life of GHRH(1-29) — described in research context, with no human dosing recommendation. What was administered, to which population, by which route — logged from the published studies, framed as research context, never as a personal protocol. ## Start here This page reports the **sermorelin** doses, routes, and pharmacokinetics that appear in published studies — and nothing more. It does not tell anyone how much to take. Peptides like sermorelin were given by injection under the skin in trials; the page also explains why the molecule is supplied as a freeze-dried powder and why it clears from the blood in minutes. Read every figure below as "studied at X in population Y," because that is exactly what it is. This is a literature digest, not a course of treatment. ## Doses used in the research literature Across the file, the studied **sermorelin dosage** figures cluster by purpose, and every one is a study observation rather than a recommendation. - **Pediatric growth-deficiency efficacy:** 30 mcg/kg/day subcutaneously at bedtime in growth-hormone-deficient children [1]. - **Aging research in older men:** 0.5 mg and 1 mg subcutaneously twice daily for 14 days, which produced dose-related GH and IGF-1 increases [2]. - **Diagnostic GHRH stimulation:** a single intravenous bolus (commonly ~1 mcg/kg) historically used to test pituitary growth-hormone reserve. - **Pharmacokinetic study:** intravenous doses of 0.25-2 mcg/kg elicited growth-hormone release in healthy men, with maximal release at 1-2 mcg/kg [3]. The pattern across these is consistent. Sermorelin was dosed to a body-weight amount (mcg/kg) or a fixed-milligram amount, given by injection, on an intermittent schedule — never a continuous drip — which matches the pulsatile mechanism described on [the GHRH(1-29) research record](/research) [12]. The figures also span very different purposes: a once-daily growth dose in children, a twice-daily research dose in older men, and a single bolus for diagnostic or pharmacokinetic testing [1][2][3]. Reading any one of them as a personal protocol would ignore the population and purpose it was studied in. None of these figures is a recommendation; each is a study observation, and this page reports them as exactly that. ## Sermorelin half-life Native GHRH(1-29) has a short plasma half-life on the order of ~10-12 minutes after intravenous administration — it is rapidly eliminated [3]. Yet a single dose elevates serum growth hormone for roughly 3 hours, because the peptide triggers a pulse that outlasts its own presence in the blood [3]. The distinction is worth holding onto: the half-life describes how long the drug stays in circulation, while the ~3-hour growth-hormone elevation describes how long the downstream effect lasts. They are not the same number, and conflating them is a common error. That brevity also fits the mechanism rather than fighting it. The pituitary reads a pulsatile signal; a short-lived peptide delivers exactly that — a discrete burst rather than a sustained occupancy of the receptor [12]. Pulsatile GHRH delivery preserved growth-hormone responsiveness better than a continuous infusion in normal men, which suggests the brief signal is a feature of the native system, not merely a pharmacokinetic limitation [12]. Still, the short half-life is the design constraint behind the whole longer-acting-analog field. The native peptide's brevity motivated stabilized analogs — the D-Ala2 substitution and the DAC (Drug Affinity Complex) albumin-binding technology behind CJC-1295, and the stabilized analog tesamorelin used in the cognition and body-composition trials [3][14]. The trade-off is mechanistic: a longer half-life moves away from the brief, pulse-like native signal toward a more sustained stimulus, which is a different pharmacology, not strictly a better one. ## Routes studied Three routes appear in the literature, with sharply different bioavailability. Subcutaneous injection is the primary studied route — used in the pediatric efficacy trial and the older-men aging study [1][2]. Intravenous dosing appears in the diagnostic and pharmacokinetic work [3]. Intranasal administration was examined historically but reached a bioavailability of only ~3-5% [3], which is why mucosal, oral, sublingual, and troche "sermorelin" formulations are widely criticized in research-user communities as poorly absorbed — peptides are degraded in the gut and cross mucosa inefficiently. The bioavailability number is the simplest reason the injectable route dominates the studied record. ## Sermorelin acetate The compound is supplied as **sermorelin acetate** — the acetate salt of GHRH(1-29), a lyophilized (freeze-dried) powder. Lyophilization exists because aqueous peptide solutions degrade: GHRH(1-29) is supplied dry and reconstituted with sterile diluent when needed, after which it is typically refrigerated. The molecule is the amidated 29-residue N-terminal fragment of GHRH, molecular weight 3357.9 Da, CAS 86168-78-7 — defined chemistry, which is part of why a 29-amino-acid fragment was chosen over the full 44-residue hormone [14]. The salt and powder facts also explain the route picture covered above. A peptide fragile enough to require freeze-drying for storage is, unsurprisingly, poorly suited to the gut, which is consistent with the very low ~3-5% intranasal bioavailability reported for GHRH(1-29) and the poor regard for oral and sublingual formulations [3]. Compounded preparations are prepared under USP <797> sterile-compounding standards, reflecting sermorelin's present status as a Category 1 bulk drug substance under FDA's interim Section 503A policy. The acetate salt, the lyophilized form, and the compounding standard are handling, stability, and regulatory facts about the material — not dosing guidance, and not a recommendation to obtain or use it. ## Why is it recommended to inject sermorelin at night? Endogenous growth hormone is secreted in pulses concentrated during slow-wave sleep, so bedtime administration in studies aligned GHRH stimulation with the body's natural nocturnal growth-hormone pulse [12]. This describes study protocols — the pediatric trial and the cognition trial both dosed at bedtime [1][6] — not a personal dosing instruction. ## When is the best time to take sermorelin? Studies typically administered GHRH-axis stimulation at bedtime to coincide with natural nocturnal, slow-wave-sleep growth-hormone pulses [1][6][12]. This reflects research protocols and is not a personal dosing recommendation. --- A constructivist reading board for the sermorelin record — every GHRH(1-29) figure logged to its study and the empty long-term adult-evidence members left openly unfilled; sermorelin was a medicine, is read here as research, and nothing on this board is dispensed, prescribed, or sold.