As studied / GHRH(1-29)
Sermorelin dosage, as it appears in the research record
The doses, routes, and durations used in published GH-axis studies — reported as study parameters, with no human dosing instruction given.
The short version
This page reports the sermorelin dosage figures that appear in studies — it does not tell anyone what to take. Research-grade sermorelin is summarized here as published science, not as a compounded prescription or a finished drug. In the literature, doses are given by weight (micrograms per kilogram, mcg/kg) or as fixed milligram amounts, almost always by subcutaneous (under-the-skin) injection. Older-men studies used 0.5 mg and 1 mg twice daily [2]; pediatric work used 30 mcg/kg per day at bedtime [1]. Everything below is framed as "studied at X in this population," never as a recommendation.
Doses used in the published studies
The research doses cluster by population. In the pediatric efficacy study, sermorelin was given at 30 mcg/kg/day subcutaneously at bedtime, accelerating first-year height velocity in GH-deficient children [1]. In aging research, healthy older men received 0.5 mg and 1 mg subcutaneously twice daily for 14 days, where the higher dose produced the fuller reversal of the age-related GH/IGF-1 decline [2]. In pharmacokinetic work, intravenous doses of 0.25-2 mcg/kg elicited GH release in healthy men, with the maximal response 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 study parameters reported for completeness. They are not converted into, and must not be read as, a human protocol — the populations, endpoints, and clinical supervision behind each figure are part of the result.
Is 500 mcg daily adequate, or should the dose be 1 mg?
Research in older men used 0.5 mg and 1 mg subcutaneous twice daily, where the higher dose produced the fuller reversal of age-related GH/IGF-1 decline [2]. These are reported as studied doses in research populations, not as a recommendation for any individual.
Why the studied doses split by population
The gap between the pediatric and adult numbers is not arbitrary. Pediatric dosing was weight-based (30 mcg/kg/day) because the endpoint was linear growth in children whose own GHRH-driven axis was deficient [1]; the adult aging studies used fixed milligram amounts (0.5 mg and 1 mg) because the endpoint was reversing an age-related decline in 24-hour GH and IGF-1 in men whose axis was intact but downshifted [2]. Different deficits, different endpoints, different dosing logic.
The chronic-stimulation literature in low-output adults reinforces why duration and dose interact. In older men and women with decreased GH secretion and low serum IGF-1, continuous subcutaneous GHRP-2 over 30 days raised pulsatile GH and serum IGF-1 within 24 hours and held it elevated [10] — a reminder that the axis-level response (IGF-1) accumulates over days even though each GH pulse is brief. None of these figures is offered as a target for any person; they are the parameters the studies happened to use.
Routes and the very short half-life
Subcutaneous injection is the primary studied route; intravenous administration appears in diagnostic and pharmacokinetic studies; intranasal delivery was examined historically but reached only 3-5% bioavailability [3]. That last figure is also why oral, sublingual, and troche "sermorelin" preparations draw heavy criticism in research-user communities — peptides are degraded in the gut and poorly absorbed across mucosa, consistent with the very low intranasal number.
The half-life governs the dosing logic. Sermorelin's plasma half-life is roughly 10-12 minutes after intravenous dosing, yet a single dose elevates serum GH for about 3 hours [3]. The peptide clears in minutes; the GH pulse it triggers does the downstream work. The brevity is precisely what longer-acting GHRH analogs were engineered to overcome.
Reconstitution, stability, and duration in studies
Lyophilized (freeze-dried) sermorelin acetate is reconstituted with a sterile diluent and, once in solution, is typically refrigerated. Aqueous peptide solutions degrade over time, which is why GHRH(1-29) is supplied as a lyophilized powder rather than a ready liquid; compounded preparations are prepared under USP <797> sterile-compounding standards.
Study durations span the timescales of the axis. Adult GH-axis studies measured changes over 14 to 30 days [2][10]; the cognition RCT ran 20 weeks [6]; pediatric growth outcomes were assessed across the first year of therapy [1]. The literature summarized here does not define an optimal duration for adult use — a gap, not a guideline. The detailed pharmacokinetics sit on the sermorelin half-life section of the research page.