Selective GH Secretagogue

IPAMORELIN

A highly selective growth hormone-releasing peptide that stimulates GH secretion through the ghrelin receptor without elevating cortisol, prolactin, or appetite.

◆ Evidence Level: Limited Human DataIpamorelin has been studied in a limited number of human trials. It is the first selective growth hormone secretagogue identified, but is not FDA-approved for any indication. See references →

What Is Ipamorelin?

Ipamorelin is a synthetic pentapeptide (five amino acids: Aib-His-D-2-Nal-D-Phe-Lys-NH2) classified as a growth hormone-releasing peptide (GHRP). It acts on the ghrelin/GHS receptor (GHS-R1a) to stimulate pituitary GH release, but unlike older GHRPs such as GHRP-6 and GHRP-2, ipamorelin is remarkably selective.

This selectivity means it triggers GH release without significantly increasing cortisol, aldosterone, prolactin, or appetite – side effects commonly associated with other ghrelin-receptor agonists. This clean side-effect profile has made ipamorelin one of the most widely used GH secretagogues in peptide research.

Mechanism of Action

Ipamorelin stimulates GH release through a pathway complementary to GHRH analogs like CJC-1295. While GHRH amplifies the amplitude of each GH pulse, ipamorelin increases the frequency of pulses through a separate receptor:

Binds the GHS-R1a (ghrelin) receptor on pituitary somatotrophs
Triggers GH release independently of the GHRH receptor pathway
Does not significantly activate cortisol or prolactin release at standard doses
Minimal impact on appetite compared to GHRP-6 or hexarelin
Synergizes powerfully with GHRH analogs (CJC-1295) for amplified GH output
Preserves natural somatostatin feedback, preventing GH overproduction

Research Applications

Clean GH elevation without cortisol or prolactin interference
Body composition optimization (fat loss with lean mass preservation)
Deep sleep enhancement and sleep architecture research
Anti-aging and skin/hair/nail quality studies
Synergistic protocols with CJC-1295 (No DAC) for amplified GH
Recovery and injury repair models with minimal side effects

Dosing Protocol

Ipamorelin is administered via subcutaneous injection 2 – 3 times daily on an empty stomach. The protocol below reflects commonly reported research dosing:

Protocol	Dose	Frequency	Notes
Standalone	200 – 300 mcg	2 – 3x daily	Fasted, before meals or bedtime
With CJC-1295	100 mcg each	2 – 3x daily	Combined injection, synergistic
Pre-bed only	200 – 300 mcg	Once nightly	Amplifies nocturnal GH surge

Inject subcutaneously on an empty stomach. Avoid food for 20 – 30 minutes post-injection. The pre-bed dose is considered the most impactful window. Typical research cycles run 8 – 16 weeks.

Preparation & Storage

Reconstitution

Supplies: peptide vial, bacteriostatic water, insulin syringes (29–31 gauge), alcohol swabs.

Clean both vial tops with alcohol swabs and let dry
Draw 2 mL of bacteriostatic water into the syringe
Insert needle into peptide vial at an angle against the glass wall
Let water run slowly down the side – never squirt directly onto powder
Gently swirl until fully dissolved – never shake
Solution should be clear – discard if cloudy or contains particles

Concentration: 5 mg in 2 mL = 2,500 mcg/mL

Storage

Unreconstituted: Room temp or refrigerated, stable up to 24 months
Reconstituted: Refrigerate at 2–8°C (36–46°F), use within 4–6 weeks
Protect from direct sunlight and heat
Do not freeze reconstituted solution

Cycling

Typical research cycle: 8–12 weeks. Results generally reported within 2–4 weeks.