Sermorelin dosage, as the studies documented it

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This page reports the sermorelin dosage figures that appear in published studies — the amounts researchers gave, to which subjects, by which route. It is not a dosing guide. Sermorelin here is research-grade laboratory material, not a compounded prescription or finished medicine, so there are no human dosing instructions on this site — only 'studied at X in [population]' descriptions. The numbers are precise where the studies are precise, and labeled as research context throughout. For why timing comes up so often, the short answer is that growth hormone surges during deep sleep, which is covered below.

Doses used in the research literature

Sermorelin dosage in the literature clusters by setting. In the pediatric GH-deficiency efficacy study, GHRH(1-29) was given at 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 ^[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 pituitary GH reserve.

These are administered study doses, reported to document the research record — not a protocol to follow.

Half-life and pharmacokinetics

Sermorelin's half-life is short: on the order of 10-12 minutes in plasma after intravenous administration ^[3]. The peptide is rapidly eliminated, yet a single dose elevates serum GH for roughly 3 hours ^[3] — the triggered GH pulse substantially outlasts the molecule itself. That gap between a ~10-12 minute half-life and a ~3 hour GH elevation is the single most useful fact for reading sermorelin's pharmacokinetics: the drug's job is to trip a pulse, not to stay in circulation, so its own short residence time does not limit the duration of its effect. That brevity is also the reason longer-acting analogs were engineered: the D-Ala2 substitution and the DAC technology behind CJC-1295 exist specifically to extend GHRH-agonist half-life ^[13]. The contrast is a clean way to read the class — sermorelin delivers a brief physiologic pulse; the stabilized analogs deliver prolonged exposure.

Routes studied

Three routes appear in the record, with very different efficiency. Subcutaneous injection is the primary research route ^[1][2]. Intravenous administration was used in diagnostic and pharmacokinetic studies ^[3]. Intranasal delivery was tested historically but reached a bioavailability of only 3-5% ^[3] — a finding consistent with the broader criticism that oral, sublingual, and troche 'sermorelin' formulations are ineffective, because peptides are degraded in the gut and poorly absorbed across mucosa. Route is not a detail here; it is most of whether any dose reaches the receptor.

Why is sermorelin studied with bedtime dosing?

Growth hormone is secreted in pulses concentrated during slow-wave sleep, and GHRH itself promotes slow-wave sleep ^[12]; the pediatric efficacy regimen used a bedtime subcutaneous dose ^[1], aligning administration with the body's natural nocturnal GH surge. Because GHRH's sleep-endocrine effects also depend on the time of administration ^[10], the timing is mechanistically motivated rather than arbitrary — it stacks an exogenous signal on top of the body's own nightly peak.

Why the dose figures vary so much across studies

The wide spread in reported numbers — 30 mcg/kg/day in children ^[1], 0.5-1 mg twice daily in older men ^[2], 0.25-2 mcg/kg intravenously in pharmacokinetic work ^[3] — is not inconsistency; it tracks the question each study was asking. Pediatric efficacy work optimized for growth over months ^[1]. Aging studies asked whether two weeks could move GH and IGF-1 in older adults ^[2]. Pharmacokinetic studies mapped the minimum dose that triggers measurable GH release and how long it lasts ^[3]. Route changes the picture again: an intravenous microgram-per-kilogram bolus and a subcutaneous milligram dose are not comparable, because subcutaneous delivery and intravenous delivery reach the receptor differently. The figures are only meaningful read together with the population, the route, and the endpoint each came from.

Stability and reconstitution notes

Lyophilized (freeze-dried) sermorelin acetate is the supplied form precisely because aqueous peptide solutions are prone to degradation ^[13]. In research handling it is reconstituted with sterile diluent and then typically refrigerated. Compounded preparations are prepared under USP sterile-compounding standards. These are storage and handling notes drawn from the research and compounding context — not instructions for human use.