Sermorelin dosage: the doses studied in the research record

In plain English

This page on sermorelin dosage describes the amounts used in published studies — it does not tell anyone what to take. Sermorelin is supplied for laboratory research, not as a medicine to self-administer, so what follows is a record of doses, routes (mostly an injection under the skin), and how long each study ran. In short: children in the efficacy trials got a weight-based dose once nightly; older men in the aging studies got a fixed dose twice a day for two weeks; and a few diagnostic studies used a single dose into a vein. The figures are reported with the study that used them.

Sermorelin dosage: doses studied in the research record

The doses below describe what studies administered, framed as research findings — not instructions, and not a recommendation. Sermorelin is described here as a research peptide; this digest gives no human dosing guidance, and the figures should be read as a log of what investigators did, not as a protocol to follow.

The pediatric efficacy work used a single daily subcutaneous dose of 30 mcg/kg/day, given at bedtime ^[1][7]. The dose is weight-based — micrograms per kilogram of body weight — which is the usual way pediatric endocrine dosing is expressed, and it was delivered once nightly rather than spread across the day. Long-term pediatric dosing at that 30 mcg/kg/day level continued for 12-24 months in one cohort, where GHRH antibodies appeared in some responders without interfering with growth and no changes in glucose or lipids were noted ^[7]. A comparison study took the question further, dosing prepubertal children at 30 or 60 mcg/kg/day subcutaneously in three daily doses; height velocity was lowest in the low-dose group but, at the high dose, reached a level comparable to growth hormone over six months ^[10] — a hint that, within the studied range, more GHRH stimulus produced more growth response up to a point.

Adult GH-axis research used a different scheme entirely: fixed milligram doses of 0.5 mg and 1 mg subcutaneously twice daily for 14 days in healthy older men, which produced dose-related GH and IGF-1 increases, with the high dose bringing those values in line with young men ^[2]. Note the contrast in design — weight-based once-nightly dosing in the growth studies, fixed twice-daily dosing in the aging studies — reflecting two different research questions rather than one consensus regimen.

Pharmacokinetic and diagnostic studies used intravenous dosing on a much smaller scale: 0.25-2 mcg/kg elicited GH release in healthy men, with 1-2 mcg/kg maximal ^[3], and a single intravenous bolus near 1 mcg/kg was historically used to probe the pituitary's capacity to release GH — a GH stimulation test ^[8]. These diagnostic doses are far lower than the therapeutic subcutaneous regimens, because the goal was to read the gland's response, not to sustain an effect.

Routes studied and formulation notes

Subcutaneous injection — an injection into the fat layer just under the skin — is the primary route across the efficacy literature ^[1][2][7]. Intravenous dosing appears in the diagnostic and pharmacokinetic studies ^[3][8], where the aim was a precise, immediate blood level for measurement rather than a sustained effect. Intranasal administration was tried historically but performed poorly: bioavailability was only 3-5% ^[3], meaning the overwhelming majority of an intranasal dose never reached circulation in active form.

That low intranasal number matters beyond its own study, because it is consistent with the research-community view that oral, sublingual, and troche "sermorelin" formulations are largely ineffective. Peptides are degraded by digestive enzymes in the gut and absorbed poorly across the mouth's mucous membranes, so a route that has to cross those barriers tends to deliver very little intact peptide — the 3-5% intranasal figure is the closest measured proxy for how steep that penalty is ^[3].

On handling, lyophilized (freeze-dried) sermorelin acetate is reconstituted with a sterile diluent and, once reconstituted, typically refrigerated; aqueous peptide solutions are prone to degradation, which is why GHRH(1-29) is supplied as a lyophilized powder rather than a ready-made liquid. Compounded preparations are prepared under USP <797> sterile-compounding standards. These are formulation observations drawn from the literature and from compounding practice, not preparation instructions, and nothing here should be read as a how-to.

Why night-time administration is studied

Growth hormone is released mostly in pulses during slow-wave (deep) sleep, so bedtime dosing aligns the stimulus with the body's natural nocturnal GH pulse; the pediatric efficacy trial dosed subcutaneously once daily at bedtime ^[1]. The logic is to work with the body's clock rather than against it — GHRH itself has a recognized physiologic role in slow-wave sleep, so a bedtime GHRH stimulus arrives when the somatotrophs are already primed to fire. This is a description of the timing investigators used and the rationale they gave, not a protocol recommendation; the digest reports it as a feature of the study design.

When is sermorelin studied as being administered?

Bedtime is the timing used in the literature, because it coincides with the body's natural nocturnal, slow-wave-sleep GH pulse; the pediatric efficacy trial dosed once daily at bedtime subcutaneously ^[1]. The adult aging studies dosed twice daily over 14 days ^[2]. This digest reports those timings rather than recommending one.

How long were studies run?

Study durations varied widely. Adult GH/IGF-1 effects were measured over 14 days ^[2], a GHRH-analog cognition trial ran 20 weeks ^[6], and pediatric growth trials ran 6 to 24 months ^[7][10]. This digest reports those windows rather than recommending a course length; "how long is enough" is a clinical question outside its scope.