Sermorelin dosage, as recorded in the research literature.

Before the details

This page reports the sermorelin dosage numbers used in published studies — which species, which dose, which route — and nothing more. It is not a protocol. Research-grade sermorelin is supplied as a lyophilized powder for laboratory study, and the figures below are study parameters, written in "studied at X in [population]" form. The key pharmacology fact to hold onto: sermorelin clears from the blood in minutes, yet a single dose can keep growth hormone elevated for about three hours — which is why studies dosed it the way they did.

Doses used in the research literature

The doses in the sermorelin record span pediatric efficacy, adult aging research, and pharmacokinetic characterization. None of the following is a human recommendation; each is a study parameter.

• Pediatric GH-deficiency efficacy: 30 mcg/kg/day subcutaneously at bedtime in the multicenter pediatric trial ^[1]; long-term pediatric studies used 30 or 60 mcg/kg/day ^[10][26].
• 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].
• Adult somatotropic-axis activation: 10 mcg/kg nightly for 16 weeks in age-advanced adults ^[25].
• Pharmacokinetic / diagnostic: intravenous doses of 0.25-2 mcg/kg elicited GH release in healthy men, with maximal release at 1-2 mcg/kg ^[3].

The consistent thread is dose-responsiveness: across routes, more GHRH(1-29) produced more GH, up to a plateau ^[3][11].

Half-life and pharmacokinetics

Native sermorelin is short-lived. GHRH(1-29) has a plasma half-life on the order of about 10-12 minutes after intravenous administration and is rapidly eliminated — yet a single intravenous dose elevated serum GH for roughly 3 hours ^[3]. The hormone the peptide triggers outlasts the peptide itself.

That brevity is the engineering problem the whole analogue family was built to solve. Incorporating D-Ala2 into GHRH(1-29)NH2 increased the peptide's half-life and decreased its metabolic clearance in normal men ^[17], and a review of PEGylation of GHRH (GRF) analogues catalogued chemical strategies to prolong the action of these short-lived peptides ^[8]. The long-acting DAC analogue CJC-1295 is the clinical expression of that same idea (see sermorelin vs CJC-1295).

Routes studied

Three routes appear in the sermorelin literature, with markedly different efficiency.

• Subcutaneous — the primary route in efficacy and aging studies ^[1][2][25].
• Intravenous — used in diagnostic GH-stimulation testing and pharmacokinetic work ^[3].
• Intranasal — characterized historically, but with bioavailability of only about 3-5% ^[3].

A dose-response study of the [Nle27]GHRH(1-29)-NH2 analogue across all three routes found a roughly tenfold higher subcutaneous and thirtyfold higher intranasal dose was required relative to intravenous to achieve comparable GH stimulation ^[11]. The poor mucosal absorption is also why oral, sublingual, and troche "sermorelin" formulations are widely criticized in research-user communities — peptides are degraded in the gut and poorly absorbed across mucosa.

Formulation and stability

Lyophilized sermorelin acetate is reconstituted with sterile diluent and, once in solution, typically refrigerated. Aqueous peptide solutions are susceptible to degradation, which is why GHRH(1-29) is supplied as a lyophilized powder rather than a ready-to-use liquid. In the compounding context, preparations are made under USP <797> sterile-compounding standards. For laboratory research material, the same handling logic applies: keep the powder dry and cold, reconstitute fresh, and treat the solution as perishable. None of this constitutes preparation guidance for human use.