Ipamorelin

Regulatory status

Not FDA-approved. Included in FDA compounding-risk communications regarding GH secretagogues.

What the evidence shows

Characterized in the late 1990s (Raun 1998). The largest human program — a phase-II trial for postoperative ileus — did not meet its endpoints and development stopped. Long-term human safety at “wellness” doses has never been studied.

Human evidence

Small pharmacology studies plus one failed phase-II program (postoperative ileus).

Animal & preclinical evidence

Well-characterized GH-release pharmacology in multiple species.

Proposed mechanism

Selectively agonizes the ghrelin (GHS-R1a) receptor on the pituitary, triggering pulsatile GH release while largely sparing ACTH/cortisol and prolactin at studied doses.

Potential risks

• Long-term safety at repeated doses unknown
• GH-axis effects: water retention, insulin sensitivity changes
• Unregulated sourcing carries purity and dosing risk
• Appetite stimulation via ghrelin agonism

Contraindications

• Active malignancy
• Uncontrolled diabetes
• Pregnancy and breastfeeding

Common research endpoints

• GH pulse amplitude and AUC
• IGF-1 response
• GI motility (failed phase-II endpoint)