GH Secretagogues

Ipamorelin

Molecular Identifiers

Molecular Formula

C38H49N9O5

CAS Number

170851-70-4

PubChem CID

9831659

Molecular Weight

711.85 Da

Overview

Third-generation GH secretagogue with a highly selective profile. Synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that acts as a selective agonist of the ghrelin receptor (GHS-R1a). Does not significantly elevate cortisol, prolactin, or ACTH.

The main clinical interest around Ipamorelin is stimulating physiological pituitary GH secretion without the hormonal side effects of earlier GHRPs: it does not significantly elevate cortisol, prolactin, or ACTH. This selective profile translates into improvements in body composition, sleep quality, tissue recovery, and general well-being, while preserving the endogenous pulsatile GH pattern. It is usually combined with a GHRH analog (CJC-1295 or Mod GRF 1-29) for a synergistic effect.

Ipamorelin currently has no regulatory approval from any agency (FDA, EMA, ANVISA). It is most often dispensed by compounding pharmacies as off-label use, in 8-12 week cycles with subcutaneous administration in the morning, post-workout, and before bed. It is considered the GHRP with the best safety profile available. WADA lists all GH secretagogues, including Ipamorelin, as substances prohibited at all times for competitive athletes.

Among GHRPs, Ipamorelin is the most selective: it does not raise cortisol, prolactin, or appetite — the opposite of GHRP-6 (strong hunger stimulus), GHRP-2 (moderate cortisol/prolactin rise), and hexarelin (more potent but with desensitization and hormonal impact). Unlike GHRH analogs (sermorelin, CJC-1295, tesamorelin) it acts on the GHS-R1a receptor and is therefore typically stacked with one of them for GHRH+GHRP synergy; oral MK-677 is the long-acting alternative on the same axis, at the cost of more water retention and glycemic impact.

Extended notation: Aib-His-D-2-Nal-D-Phe-Lys-NH₂

Contains D-amino acids and non-natural amino acids (Aib, D-2-Nal, D-Phe)

Half-life

~2 hours

Administration Route

Subcutaneous

Category

GH Secretagogues

Mechanism of Action

  • Selective agonism of the GHS-R1a receptor (ghrelin receptor)
  • Dose-dependent GH stimulation from the anterior pituitary
  • Synergism with GHRH (CJC-1295/Mod GRF 1-29)
  • No significant elevation of cortisol or prolactin
  • Preserves the physiological pulsatile pattern of GH secretion

Dosage Protocol

Data compiled from the literature. This does not constitute medical advice.

Parameter Value
Dose 200-300 mcg per injection
Frequency 2-3 times daily
Timing Morning, post-workout, and before bed
Duration 8-12 weeks

Reported Side Effects

Adverse effects described in the literature. Severity and frequency vary between individuals.

  • Headache
  • Mild nausea
  • Facial flushing
  • Tingling

Product Properties

Purity >99%
Appearance White lyophilized powder
Solubility Soluble in bacteriostatic water
Source Solid-phase peptide synthesis (SPPS)
Storage Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 4 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles.

Presentations & Preparation

Vials of Ipamorelin found in the research market:

2 mg5 mg10 mg

Reconstitution

  • Diluent: Bacteriostatic water
  • Volume: 2 ml per 5 mg vial
  • Inject slowly against the vial wall
  • Gently swirl until fully dissolved
  • Never shake

Storage

  • Lyophilized: Room temperature (up to 24 months)
  • Reconstituted: Refrigerated 2-8°C (up to 4-6 weeks)
  • Do not freeze after reconstitution
  • Protect from direct light
Reconstitution Calculator

Scientific Studies

Published studies on Ipamorelin.

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