What Is Ipamorelin? Dosage, Half-Life & How to Track It

What Ipamorelin is and how it works

Ipamorelin is a synthetic pentapeptide — five amino acids — originally developed by Novo Nordisk (research code NNC 26-0161) as a growth-hormone secretagogue. Like the other GHRPs in this family, it works by mimicking ghrelin, the "hunger hormone," at the GH secretagogue receptor (GHS-R1a) in the pituitary and hypothalamus, which triggers a pulse of growth-hormone release.

What sets Ipamorelin apart is selectivity. GHRP-2 and GHRP-6 also nudge up cortisol, prolactin, and appetite as a side effect of their mechanism; Ipamorelin was specifically selected in development for not doing that, at least at typical doses. That is the main reason it has become the default GHRP for people who want a GH pulse without the hunger spike or the hormonal noise.

Because it only stimulates GH release through the pituitary’s own machinery — rather than replacing GH directly — the pulse it produces still passes through the body’s normal feedback loop. Somatostatin can still cap it, which is part of why pairing Ipamorelin with a GHRH analog produces a bigger effect than either alone.

Typical dosing & reconstitution

Ipamorelin ships as a lyophilized powder reconstituted with bacteriostatic water. Community protocols cluster around 100–300 mcg subcutaneously once daily, most often at bedtime to align with the body’s largest natural GH pulse; some users split that into two or three smaller injections across the day instead.

How much BAC water you add determines concentration, and concentration determines the syringe units for a given dose:

At 1.67 mg/mL, a 200 mcg dose is 12 units on a standard U-100 insulin syringe. For doses under about 10 units, a 30- or 50-unit syringe reads more accurately — exactly the kind of detail the reconstitution calculator sorts out automatically.

Half-life & what it means for frequency

Ipamorelin clears from the blood in roughly 2 hours — short enough that a single injection produces one clean GH pulse rather than a sustained elevation. That is by design: GH released in short, natural pulses matches how the body already secretes it, rather than holding levels artificially high around the clock.

The practical effect is that timing matters more than it would for a long-ester compound. Dosing at bedtime rides the body’s biggest natural nocturnal GH pulse, and dosing on an empty stomach matters too — a recent meal, especially one high in carbs or fat, blunts the ghrelin-receptor response.

What to track & common side effects

Ipamorelin’s side-effect profile is generally mild — the most common complaints are injection-site redness, mild water retention, and occasionally a brief flush or tingling right after the shot. It largely spares people the appetite spike and cortisol/prolactin bump that come with GHRP-2 or GHRP-6, which is the main reason it is the more commonly recommended starting GHRP.

Because it is usually run as a nightly habit for months, the easy thing to lose is the streak — did last night actually happen? Logging each dose alongside sleep quality, recovery, and body-composition trends (and IGF-1 if you lab it) turns "I think it’s working" into something you can actually see.

Frequently asked questions