Overview
Sermorelin is a growth hormone-related peptide. Synthetic GHRH analog (first 29 amino acids of endogenous GHRH).
With a half-life of ~10 minutes, Sermorelin requires daily administration in most observed protocols. Administered via SubQ injection, it has a bioavailability of approximately 95% via its primary route.
Half-life approximately 10 minutes. Very rapid plasma clearance. Previously FDA-approved as a diagnostic agent. Subcutaneous administration. One-compartment model.
Mechanism of Action
Sermorelin's pharmacological activity involves the following key pathways:
GHRH Receptor Activation
Sermorelin binds to growth hormone-releasing hormone (GHRH) receptors on somatotroph cells in the anterior pituitary, stimulating GH synthesis and secretion.
Pulsatile GH Release
Activation of GHRH receptors promotes GH release in a pulsatile pattern that more closely mimics physiological secretion compared to exogenous GH administration.
Dosing Protocols
The following protocols represent commonly observed dosing patterns. These are observational summaries, not recommendations.
Dose
200 mcg/day
Route
Subcutaneous
Frequency
2-3 times daily
Duration
4-12 weeks
Dose
500 mcg/day
Route
Subcutaneous
Frequency
2-3 times daily
Duration
4-12 weeks
Reconstitution Steps
Sermorelin is supplied as a lyophilized (freeze-dried) powder and requires reconstitution before use. Common vial sizes: 2 mg, 3 mg, 5 mg, 6 mg, 9 mg.
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1
Gather supplies
You will need a vial of lyophilized sermorelin powder, bacteriostatic water (BAC water), an insulin syringe (0.5 mL or 1 mL), and an alcohol swab. Sermorelin is sensitive to agitation, so avoid vigorous shaking at any step.
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2
Clean the vial tops
Wipe the rubber stoppers of both the sermorelin vial and the BAC water vial with separate alcohol swabs. Allow both to air-dry for 10–15 seconds before proceeding.
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3
Draw bacteriostatic water
Draw 1–2 mL of bacteriostatic water into the syringe, depending on your desired final concentration. For a standard 2 mg vial reconstituted with 2 mL, the resulting concentration is 1 mg/mL (1,000 mcg/mL).
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4
Add water to the sermorelin vial
Insert the needle at an angle against the glass wall of the vial and slowly inject the BAC water so it runs down the side rather than directly onto the powder. This minimizes foaming and protects the peptide structure.
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5
Gently swirl to dissolve
Roll the vial gently between your palms or swirl in a slow circular motion for 20–30 seconds until the powder is fully dissolved. The solution should appear clear and colorless — do not use if cloudy or if particulates are visible.
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6
Label and refrigerate
Label the vial with the reconstitution date and store immediately at 2–8°C. Reconstituted sermorelin is stable for up to 30 days when refrigerated and protected from light.
Quick Reconstitution Math
2 mg vial + 2 mL BAC water = 1,000 mcg/mL. A 300 mcg dose = 0.30 mL (30 units on an insulin syringe). Use the Milligram reconstitution calculator for custom vial sizes.
Store reconstituted solution at 2–8°C. Stable for up to 30 days. Do not freeze the reconstituted vial. Lyophilized powder prior to reconstitution can be stored frozen at −20°C for extended shelf life.
Frequently Asked Questions
What is Sermorelin and how does it work?
Sermorelin is a synthetic 29–amino acid peptide representing the active fragment of endogenous growth hormone-releasing hormone (GHRH 1–29). It binds to GHRH receptors in the pituitary gland, stimulating the natural pulsatile release of growth hormone. Because its action is regulated by somatostatin feedback, GH release mirrors the body's own physiological rhythm rather than producing the constant supraphysiological levels associated with exogenous GH injections.
What is the half-life of Sermorelin and how often should it be dosed?
Sermorelin has a very short half-life of approximately 10–12 minutes after subcutaneous administration, with peak serum concentrations reached within 5–20 minutes post-injection. Due to this rapid clearance, once–daily dosing before bedtime is the most commonly observed protocol, aligning GH stimulation with the body's natural nocturnal growth hormone surge. Some protocols split doses across two or three injections daily for broader GH pulse coverage.
How long does Sermorelin take to show effects?
Sleep quality improvements are commonly reported within the first 2–4 weeks, as the enhanced nocturnal GH pulses interact with sleep architecture. Subjective changes in recovery and energy are typically noted within 4–8 weeks of consistent use. Body composition changes–such as shifts in lean mass and fat distribution–generally require 3–6 months of sustained protocol adherence.
Does Sermorelin suppress natural growth hormone production?
Sermorelin does not suppress endogenous growth hormone production because it works by stimulating the pituitary's own release mechanisms rather than bypassing them. The somatostatin feedback loop remains intact, preventing over-stimulation and maintaining normal GH regulation. This is one of the primary distinctions between sermorelin and direct exogenous HGH administration.
What compounds is Sermorelin commonly stacked with?
Sermorelin is frequently observed in combination with GHRPs such as Ipamorelin or GHRP-2, as these peptides act on complementary receptors–GHRH receptors versus ghrelin receptors–producing synergistic GH pulse amplification when combined. CJC–1295 (no DAC) is another common pairing, offering a similar GHRH mechanism with a slightly different stability profile. Some protocols also include BPC–157 or TB–500 alongside sermorelin for combined recovery and GH optimization goals.
What vial sizes and storage requirements apply to Sermorelin?
Sermorelin is commonly supplied as a lyophilized powder in 3 mg, 6 mg, and 9 mg vials for compounded clinical preparations, with 2 mg and 5 mg formats also available from research suppliers. Unreconstituted lyophilized powder should be stored at 2–8°C (refrigerated). Once reconstituted with bacteriostatic water, the solution remains stable for up to 30 days when refrigerated at 2–8°C and protected from light.