Sermorelin Doses Used in the Research Literature

The short version

This page reports sermorelin dosage the way the studies recorded it — what amount went into which group, by which route — and nothing more. It is not a how-to. Children in the growth study received a weight-based dose under the skin at bedtime; older men in the aging study got a fixed dose twice a day for two weeks. The peptide leaves the blood fast (about ten to twelve minutes), yet a single dose keeps growth hormone up for roughly three hours. Because growth hormone surges at night during deep sleep, research dosed it at bedtime. None of this is a personal dosing instruction.

Sermorelin Dosage in the Research Literature

Every sermorelin dosage figure here is best read as "studied at X in [population]," never as a recommendation. In the pediatric growth-hormone-deficiency efficacy study, GHRH(1-29) was administered at 30 mcg/kg/day subcutaneously at bedtime ^[2]. In the aging-axis study, healthy older men received 0.5 mg and 1 mg subcutaneously twice daily for 14 days, with the higher dose driving the GH/IGF-1 reversal ^[5]. For diagnostic and pharmacokinetic purposes, intravenous doses of roughly 0.25-2 mcg/kg elicited growth-hormone release in healthy men, with maximal release near 1-2 mcg/kg ^[3].

These figures describe what investigators administered in specific study populations. They are research-context observations about GHRH(1-29), not instructions for human use, and this site supplies none. Sermorelin here is research-grade material supplied for laboratory research — not a compounded prescription or finished drug. The full set of sermorelin doses used in research sits in the studies cited.

Sermorelin Half-Life and Pharmacokinetics

Sermorelin has a short plasma half-life on the order of 10-12 minutes after intravenous administration — GHRH(1-29) is cleared rapidly ^[3]. The striking part is the disconnect: despite that brief half-life, a single dose elevates serum growth hormone for roughly 3 hours, because the pulse it triggers outlasts the peptide itself ^[3]. Intranasal bioavailability was only about 3-5% in the same pharmacokinetic work ^[3], which is the usual cited reason oral, sublingual, and troche formats are doubted in research-user discussion — peptides degrade in the gut and cross mucosa poorly.

That brevity is the engineering problem the analog family was built to solve. The native fragment's quick clearance motivated longer-acting designs — the D-Ala2 substitution and the Drug Affinity Complex (DAC) albumin-binding technology behind CJC-1295 — to extend exposure. The sermorelin half-life and pharmacokinetics directly inform why research spaced doses as it did.

Routes and Stability Studied

Subcutaneous injection was the primary research route; intravenous was used in diagnostic and pharmacokinetic studies, and intranasal appeared in a historical pharmacokinetic study where bioavailability was only about 3-5% ^[3]. Lyophilized sermorelin acetate is reconstituted with sterile diluent and typically refrigerated once in solution, because aqueous peptide solutions are prone to degradation — the reason GHRH(1-29) is supplied as a freeze-dried powder. Where prepared for patients, compounded preparations are made under USP <797> sterile-compounding standards; the material discussed on these pages is research-grade and is described, not dosed.

Why Oral and Sublingual Formats Are Doubted

The route data carry a practical implication that recurs in research-user discussion. The same pharmacokinetic study that established the ~10-12 minute half-life found intranasal bioavailability of only about 3-5% ^[3] — a small fraction of the peptide crossing the nasal mucosa intact. Oral, sublingual, and troche "sermorelin" formats face the same physics and worse: peptides are degraded by digestive enzymes and absorb poorly across mucosa, so very little intact GHRH(1-29) would be expected to reach circulation.

That is why the injectable subcutaneous route dominates the research record, and why mucosal and oral preparations are widely criticized as ineffective in the literature-reading community. It is also a reminder that this is a fragile signaling peptide, not a small-molecule pill — a point about pharmacology, reported here as context rather than as any instruction for use.

Diagnostic Use of GHRH in the Older Literature

Beyond the therapeutic studies, GHRH(1-29) has a diagnostic history worth noting. A GH stimulation test gives a growth-hormone secretagogue and measures the pituitary's response to gauge its capacity to release growth hormone; GHRH was historically used this way, commonly as a single intravenous bolus near 1 mcg/kg, to probe pituitary GH reserve. The pharmacokinetic work that mapped the dose-response — GH release from doses as low as 0.25 mcg/kg, maximal near 1-2 mcg/kg ^[3] — sits directly behind that diagnostic framing. These are documented research and diagnostic doses, recorded for completeness, not a protocol for personal use.

Why Sermorelin Was Studied with Bedtime Dosing

Growth hormone is secreted in pulses, especially during slow-wave sleep, and slow-wave sleep coincides with the dominant nocturnal GH pulse ^[13]. Research protocols therefore administered GHRH(1-29) at bedtime to align with that endogenous pulse — the pediatric efficacy trial used once-daily subcutaneous bedtime dosing ^[2]. Described as a study protocol, not a dosing instruction.

When Sermorelin Was Administered in Studies

Research protocols specified bedtime administration to coincide with the dominant nocturnal GH pulse during slow-wave sleep ^[13][2]. Aligning dosing with that endogenous pulse is the rationale reported in the literature. Stated as a study-protocol observation, not a personal dosing instruction.