Ipamorelin Overview

Ipamorelin is a pentapeptide growth hormone secretagogue that selectively stimulates GH release by mimicking ghrelin at the GHS-R1a receptor. It is notable for not significantly elevating cortisol, prolactin, or ACTH at research doses, making it one of the cleanest GH secretagogues available for research.

Sermorelin Overview

Sermorelin is a truncated analog of natural GHRH, containing the first 29 amino acids needed for full biological activity. With previous FDA approval for diagnostic purposes, it has an extensive safety profile. Its short half-life of 10-20 minutes produces GH release that closely mimics the body’s natural pulsatile secretion pattern.

Head-to-Head Comparison

Feature	Ipamorelin	Sermorelin
Class	GHRP (Ghrelin mimetic)	GHRH analog
Mechanism	GHS-R1a agonist	GHRH receptor agonist
Half-Life	~2 hours	~10-20 minutes
Cortisol Effect	Minimal	Minimal
FDA History	None	Previously approved
Price (2mg)	$30-50	$30-50

Key Differences

These peptides work through entirely different pathways. Ipamorelin mimics ghrelin to trigger GH release (like pressing a button), while Sermorelin amplifies the natural GHRH signal (like turning up a dial). Ipamorelin has a longer effective window (~2 hours vs minutes). Both are considered highly selective with minimal impact on cortisol and prolactin. They are often combined in research for synergistic GH release through dual-pathway stimulation.

Which Should You Choose?

Choose Ipamorelin for research into selective ghrelin-pathway GH stimulation with a clean side effect profile. Choose Sermorelin for studies requiring natural GHRH-pathway stimulation with well-established safety data. For maximum GH axis research, many protocols combine both for synergistic effects through complementary pathways.

Frequently Asked Questions

Which produces more GH?

When used individually at comparable doses, both produce similar GH elevations. However, combining them can produce synergistic effects greater than either alone, as they stimulate GH through independent pathways.

Which is better for beginners?

Both have favorable safety profiles. Sermorelin has more published safety data due to its FDA history, while Ipamorelin is often preferred for its selectivity and lack of cortisol elevation.