Ipamorelin
Growth Hormone Secretagogue (GHRP)researchAlso known as: IPA, NNC 26-0161
A highly selective growth hormone-releasing peptide (GHRP) that stimulates GH release with minimal impact on cortisol, prolactin, or appetite, making it the cleanest GHRP available.
Overview
Ipamorelin is a synthetic pentapeptide and growth hormone secretagogue that acts by mimicking ghrelin and binding to the growth hormone secretagogue receptor (GHS-R) in the pituitary gland. What distinguishes ipamorelin from other GHRPs (GHRP-2, GHRP-6, hexarelin) is its remarkable selectivity โ it stimulates growth hormone release without significantly elevating cortisol, prolactin, or aldosterone levels, and does not strongly stimulate appetite. This clean side-effect profile makes it the most widely recommended GHRP for GH optimization. It is most commonly used in combination with Mod GRF 1-29 (CJC-1295 no DAC), known as the 'CJC/Ipa stack,' which is considered the gold standard peptide protocol for natural GH optimization in the anti-aging and biohacking communities.
Mechanism of Action
Ipamorelin works through: (1) Binding to the GHS-R1a (ghrelin receptor) on pituitary somatotrophs to initiate GH release; (2) Unlike other GHRPs, it does not significantly activate the GHS-R on adrenal cells (hence no cortisol spike) or lactotrophs (no prolactin increase); (3) Amplifies the natural GH pulse when combined with GHRH analogs through distinct but complementary signaling pathways; (4) Does not suppress the body's natural somatostatin feedback โ GH release remains regulated; (5) Demonstrates dose-dependent GH release without a ceiling effect at typical doses; (6) Minimal ghrelin-mimetic appetite effects compared to GHRP-6.
Molecular Formula
C38H49N9O5
Molecular Weight
711.85 g/mol
Sequence
Aib-His-D-2-Nal-D-Phe-Lys-NH2
Dosage Protocols
Dose Range
100mcg โ 200mcg
Frequency
1-3 times daily
Route
subcutaneous
Cycle Length
8-12 weeks on, 4 weeks off
Most popular protocol: 100-200mcg ipamorelin + 100mcg Mod GRF 1-29 before bed on empty stomach. For enhanced results, add morning and/or post-workout doses.
Source: Clinical guidance and community protocols
Side Effects
| Effect | Severity |
|---|---|
| Head rush / flushing | mild |
| Injection site irritation | mild |
| Headache | mild |
| Lightheadedness | mild |
| Increased hunger | mild |
Pros & Cons
Cleanest GHRP โ does not significantly raise cortisol, prolactin, or aldosterone
Minimal appetite stimulation compared to GHRP-6 and GHRP-2
Excellent synergy with GHRH analogs (Mod GRF 1-29) for amplified GH pulses
Very mild side effect profile โ well tolerated by most users
Promotes deep sleep quality through enhanced nocturnal GH release
Requires subcutaneous injection, typically multiple times daily for best results
Must be taken in fasted state to avoid blunting GH release
Less potent GH release per injection compared to GHRP-6 or hexarelin
Not FDA-approved; quality depends on peptide source
Effects are subtle and gradual โ not a replacement for exogenous HGH in terms of potency
Research Studies
Legal Status
Not FDA-approved. Available as a research chemical. Banned by WADA. Was in clinical development for post-surgical GI recovery but trials were not completed.
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