Sermorelin

Also known as · GHRH(1-29) · GRF 1-29 · Geref (withdrawn 2008)

01 / Dosing schedule

Cited dosing

Sermorelin was FDA-approved as Geref Diagnostic for adult GHD (1 mcg/kg single IV) and Geref Pediatric for short stature (30 mcg/kg/day subQ). Both brands were withdrawn from the US market in 2008. Adult therapeutic use today is from compounding pharmacies at the published research doses shown below.

Geref Diagnostic — adult GH-reserve test

PhaseDose & frequency
Standard dose1 mcg/kg as a single IV injection
RouteIntravenous
PurposeProvocative GH stimulation testing

Source · FDA medical review — Geref Diagnostic (referenced in Egrifta review) ↗

Adult research schedule (clinical literature)

PhaseDose & frequency
Typical starting dose200–300 mcg subQ at bedtime
FrequencyOnce daily (5–7 nights per week)
MonitoringIGF-1 at baseline, 6 weeks, 12 weeks, then every 3–6 months

Source · Corpas E et al. Human GH-releasing hormone(1-29) in older men. JCEM 1992 ↗

Source indication · Diagnostic assessment of pituitary GH reserve; pediatric GH deficiency. Adult daily use is not the approved indication.

Injection frequency
Diagnostic: single dose. Adult research use: once daily at bedtime.
Injection sites
Abdomen or thigh. Rotate sites.

02 / Reconstitution

Reconstitution reference

Research-grade sermorelin typically ships as a 5 mg or 10 mg lyophilized vial. A common prep is 5 mg with 2 mL bacteriostatic water = 2.5 mg/mL (2500 mcg/mL). At that concentration, a 250 mcg dose is 0.1 mL = 10 units on a U‑100 syringe.

Vial5 mg
BAC water2 mL
Concentration2.5 mg/mL
Example dose250 mcg
On a U‑100 syringe10 units on U‑100
Open the reconstitution calculator →

03 / Overview

Protocol overview

Sermorelin is a synthetic analog of the first 29 amino acids of endogenous GHRH — the minimum active fragment. It stimulates the pituitary to release growth hormone in a physiologic, pulsatile pattern.

The FDA-approved brand (Geref) was withdrawn from the US market in 2008. Adult therapeutic use today is entirely off the original label and sourced from compounding pharmacies.

Bedtime dosing is common because endogenous GH pulses peak during slow-wave sleep. The ~10–12 minute plasma half-life makes sermorelin a short trigger rather than a sustained agent.

Long-term efficacy and safety data at adult research doses are limited compared to somatropin. IGF-1 response is the standard surrogate marker.

04 / References

References

  1. Corpas E et al. Human growth hormone-releasing hormone(1-29) twice daily reverses the decreased GH and IGF-I levels in old men. JCEM 1992 ↗
  2. FDA medical review referencing Geref Diagnostic approval (1 mcg/kg IV) in Egrifta NDA 022505 ↗