Ipamorelin Dosage: What the Research Reports and How the Vial Math Works

Ipamorelin is a pentapeptide growth hormone secretagogue, and its defining property is selectivity. The foundational 1998 paper that introduced it described it as the first selective GH secretagogue — it prompted growth hormone release without the accompanying rises in cortisol and prolactin that characterised earlier compounds in the class.

That selectivity is the entire reason it is discussed separately from GHRP-2 and GHRP-6, and it is the only claim about it with a solid published basis.

How it works

Ipamorelin binds the ghrelin receptor (GHS-R1a) in the pituitary, prompting release of growth hormone the body already produces. It is a secretagogue, not a hormone — the distinction matters, because the ceiling is set by what the pituitary can release rather than by how much you introduce.

It is frequently paired with CJC-1295, which acts on a different receptor. See the CJC-1295 and ipamorelin guide for why those two get combined.

Why timing gets discussed

Growth hormone is released in pulses, with the largest occurring during early deep sleep. Because ipamorelin amplifies a pulsatile system rather than creating a constant level, discussions of it centre on timing relative to those natural pulses and to meals — food, particularly fat and carbohydrate, blunts the response.

That is the mechanistic rationale for the fasted-window protocols that circulate. It is a reasonable inference from how the system works, not a finding from a dose-timing trial in humans.

The vial math

Ipamorelin is supplied lyophilised, most often in 5 mg or 10 mg vials. Doses discussed in research contexts are in micrograms, which makes the concentration choice consequential: too little water and the target lands at an unreadable two or three units.

Reconstitution chart

The peptide calculator converts any vial size and target into units directly.

Storage

Storage follows the same rules as any reconstituted vial: 2–8 °C, never frozen, bounded by the shorter of peptide stability and the 28-day limit on bacteriostatic water. The bacteriostatic water guide covers that in full.

Frequently asked questions

Is ipamorelin the same as growth hormone?

No. Growth hormone is the hormone itself; ipamorelin prompts the pituitary to release its own. The mechanisms and the resulting profile are different.

What does "selective" mean here?

It refers to prompting GH release without the parallel cortisol and prolactin increases seen with earlier secretagogues. That is the specific claim the original research supports.

Why is it usually paired with CJC-1295?

They act on different receptors — ghrelin receptor versus GHRH receptor — so the rationale is complementary rather than additive stimulation of the same pathway.