# Sermorelin Dosage in the Research Literature: Doses, Routes, Half-Life

> Sermorelin dosage as studied: the subcutaneous doses used in pediatric and aging research, the routes investigated, and the ~10-12 minute plasma half-life. Research context, not advice.

The subcutaneous, intravenous, and intranasal doses recorded in the research, the routes investigated, and the short plasma half-life that motivated longer-acting analogs.

## The short version

This page records the sermorelin dosage figures that appear in published studies — what researchers gave, to whom, by which route. It is not a how-to and contains no instructions for use. Quick orientation: in the children's study, the peptide was injected under the skin once a day; in the aging study, older men received it under the skin twice a day for two weeks; and the peptide clears from the blood fast — a plasma half-life of about 10-12 minutes — even though a single dose keeps growth hormone elevated for around three hours. That fast clearance is exactly why longer-lasting versions were later engineered.

## Doses Studied in the Research Literature

The sermorelin dosage record is drawn from the trials, framed as what was administered to which population by which route — never as a recommendation. In the pediatric growth hormone-deficiency efficacy study, GHRH(1-29) was given at 30 mcg/kg/day subcutaneously at bedtime [1]. In the aging research in older men, GHRH(1-29) was administered at 0.5 mg and 1 mg subcutaneously twice daily for 14 days, producing dose-related growth hormone and IGF-1 increases [2]. In a pharmacokinetic study in 30 healthy men, intravenous doses of 0.25-2 mcg/kg elicited growth hormone release, with maximal release at 1-2 mcg/kg [3]. A diagnostic GHRH stimulation test historically used a single intravenous bolus (commonly around 1 mcg/kg) to probe pituitary growth hormone reserve.

These are [doses studied in the research](/dosage), summarized for completeness of the record. No human dosing instruction is given or implied.

## Routes Studied

Three routes appear in the literature. Subcutaneous injection is the primary route in the efficacy and aging studies [1][2]. Intravenous administration was used in diagnostic and pharmacokinetic work [3]. Intranasal administration was examined historically, but bioavailability was only about 3-5% [3] — a low figure that helps explain why research-user communities widely criticize oral, sublingual, and troche "sermorelin" formulations as ineffective: peptides are degraded in the gut and poorly absorbed across mucosa.

## Half-Life and Pharmacokinetics

Sermorelin's [half-life and pharmacokinetics](/dosage#half-life) are the defining structural fact of the molecule. GHRH(1-29) has a short plasma half-life on the order of about 10-12 minutes after intravenous administration and is rapidly eliminated, yet a single dose elevates serum growth hormone for roughly three hours [3]. That elevation despite rapid clearance reflects the kinetics of pituitary stimulation rather than persistence of the peptide itself.

The native peptide's brevity is what motivated longer-acting analogs. Substituting D-Ala at position 2 of GHRH(1-29)NH2 and adding the DAC (drug affinity complex) technology — a maleimide group that binds serum albumin to extend half-life — is the structure-activity basis behind longer-acting GHRH analogs such as CJC-1295 with DAC. That contrast is the subject of the [sermorelin vs CJC-1295](/vs-cjc-1295) comparison.

## Why timing appears in the dosing studies

The dosing record repeatedly notes time of day, not just amount. The pediatric efficacy study administered GHRH(1-29) at bedtime [1], and aging and cognition research has favored nocturnal dosing [6]. The physiologic reason is that endogenous growth hormone is released in pulses, especially during slow-wave sleep, and sleep-endocrine responses to GHRH are time-of-administration dependent [8]. Pulsatile delivery also preserves growth hormone responsiveness relative to continuous infusion [9], which is why intermittent dosing — rather than a steady drip — is the pattern that appears across the literature. This explains a feature of the study protocols; it is not a schedule to follow.

## Formulation and Stability Notes

Lyophilized sermorelin acetate is reconstituted with sterile diluent and, once reconstituted, is typically refrigerated. Aqueous peptide solutions are susceptible to degradation, which is why GHRH(1-29) is supplied as a lyophilized powder. Compounded preparations are prepared under USP <797> sterile-compounding standards. These are handling characteristics documented for the peptide, not a preparation or administration protocol.

---

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.