# Sermorelin Dosage in the Research: Routes, Half-Life & Forms

> Sermorelin dosage as studied, not prescribed: the research doses and routes, the ~10-12-minute half-life, why injection beats tablets, and what the PK data actually show.

## Read this first

This page describes the sermorelin dosage used in published research — what was given, to whom, by which route, in which study. It is not a protocol and contains no recommendation for any person to take anything. The short version: research doses were small, given by injection under the skin, and timed to work with the body's own nighttime growth-hormone rhythm. The peptide clears the blood in about ten to twelve minutes, yet a single dose keeps growth hormone up for roughly three hours [3].

One durable, evidence-based point cuts through the product marketing: tablets and other swallowed or under-the-tongue forms are poorly absorbed, because peptides are broken down in the gut and cross mucous membranes badly — consistent with the ~3-5% bioavailability measured for the intranasal route [3].

## Sermorelin dosage: what the studies administered

In the pediatric efficacy study, GHRH(1-29) was given as a once-daily subcutaneous injection at bedtime in growth-hormone-deficient children [1]. In aging research, healthy older men received 0.5 mg and 1 mg subcutaneously twice daily for 14 days [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]. Diagnostic GHRH stimulation testing historically used a single intravenous bolus (around 1 mcg/kg) to probe pituitary GH reserve. These are research and diagnostic contexts — described to inform, not to instruct.

## Half-life and why timing matters

Native GHRH(1-29) has a short plasma half-life on the order of ~10-12 minutes after intravenous administration; it is cleared rapidly, yet a single dose still elevates serum GH for about three hours [3]. That brevity is the engineering problem that motivated longer-acting analogs — the D-Ala2 substitution and the DAC (drug-affinity-complex) albumin-binding technology behind CJC-1295 exist precisely to stretch GHRH action [3]. Because the body's largest natural GH pulse occurs during slow-wave sleep, research and clinical practice favored bedtime administration so the stimulus lands with the body's own rhythm rather than against it.

## Sermorelin injection vs sermorelin tablets

Sermorelin injection (subcutaneous) is the route with essentially all of the supporting human data — the pediatric trial, the aging study, and the PK work all used parenteral administration [1][2][3]. Sermorelin tablets, sublingual drops, and troches are a different story: peptides are degraded by digestive enzymes and absorb poorly across oral and nasal mucosa, which is why the intranasal route managed only ~3-5% bioavailability in the pharmacokinetic study [3]. Research-user communities widely report oral and sublingual forms as ineffective, and the absorption data give that complaint a mechanistic basis. None of this is a purchasing or dosing recommendation — it is what the route data show.

Lyophilized (freeze-dried) sermorelin acetate is reconstituted with sterile diluent and typically refrigerated once mixed, because aqueous peptide solutions degrade; compounded preparations follow USP <797> sterile-compounding standards.

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An engineering-datasheet reading of the sermorelin record — every GHRH(1-29) figure logged to its study and stamped with an evidence grade, the proven pediatric trial kept apart from the borrowed tesamorelin numbers and both apart from the in-silico oncology and preclinical regenerative signals; no clinic behind the spec sheet and nothing here dosed, compounded, prescribed, or sold.