Ipamorelin

Ipamorelin (selective GH secretagogue)

Selective ghrelin receptor agonist · stimulates GH without prolactin/cortisol increase

FDA Status

Not FDA-approved · Investigational · Compounding restricted

Class

Pentapeptide · GHRP class

Sequence

Aib-His-D-2-Nal-D-Phe-Lys-NH2

Half-life

~2 hours

Mechanism of action

• Selective ghrelin/GHS-R1a receptor agonism
• Pulsatile GH release mimicking physiological pattern
• No significant effect on prolactin, cortisol, or aldosterone (vs older GHRPs)
• Mild effect on appetite (less than GHRP-6)

Research areas

• Growth hormone deficiency in adults
• Sarcopenia and muscle wasting (preliminary)
• Post-operative recovery
• Investigational: bone density, fat redistribution

Evidence and clinical data

Phase II human trials demonstrated GH stimulation without the side-effect profile of older GHRPs (GHRP-2, GHRP-6). Generally considered the cleanest secretagogue. Limited Phase III data.

Safety profile

Best-tolerated of the GHRP class. Common AEs: head-flush, mild headache. No significant cortisol or prolactin shifts. Long-term IGF-1 trajectory needs more data.