All peptides
Growth hormoneModerate

Ipamorelin

NNC 26-0161

The most selective of the growth-hormone secretagogues, valued because it lifts GH without meaningfully raising cortisol or prolactin.

How it works

Acts as a ghrelin receptor (GHS-R1a) agonist on the pituitary, triggering a clean GH pulse. Its selectivity avoids the appetite and cortisol effects seen with older secretagogues like GHRP-6.

Structure: Pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2)

Reported benefits

  • Clean GH pulse without hunger spikes
  • Better sleep quality and recovery
  • Mild fat-loss and body-composition support

Practical considerations

  • Weakest GH release of the GHRPs — usually stacked with CJC-1295
  • Effects build over weeks, not days
  • Dose ceiling: more than ~300 mcg per pulse gives diminishing returns

Side effects and risks

  • Mild headache
  • Injection-site redness
  • Light-headedness shortly after dosing

Dosing overview

200–300 mcg per dose, often 100–300 mcg before bed

This describes doses reported in published literature and community protocols. It is not a recommendation, and it is not a substitute for clinical supervision.

Research references

  • Raun et al., 1998 — Ipamorelin, the first selective growth hormone secretagogue