Peptides.info

Ghrelin-receptor / GH secretagogue

Ipamorelin

Preclinical

The selective GH pulse without the cortisol baggage.

Cited sources
1
Human-tested claims
0 of 2
Best evidence
Tier 3 · Preclinical
Status
Research-only

A pentapeptide ghrelin-receptor agonist that triggers growth-hormone release with little effect on cortisol or prolactin — the selectivity that made it a research favorite. It works by a different mechanism than the GHRH analogs, and human evidence is thin; the foundational work is preclinical.

GH-axissecretagogueinvestigational

How it works

Ipamorelin acts on the ghrelin receptor (GHS-R1a), the same 'hunger hormone' receptor that stimulates growth-hormone secretion — a distinct route from GHRH analogs like tesamorelin. Its appeal in early studies was selectivity: a clean GH pulse without a matching rise in cortisol or prolactin.

Sequence: Aib-His-D-2-Nal-D-Phe-Lys-NH₂A pentapeptide with non-natural residues (Aib, D-2-naphthylalanine, D-Phe), so it has no valid one-letter representation — shown in three-letter form.

What it's studied for

One claim per card, each with its own tier and source. Tiers 1 and 2 are human data. Tiers 3 and 4 are not yet.

Regulatory & legal status

Research-only

Not approved; investigational. Explored for post-operative ileus but never reached approval; no long-term human safety data.

[1]Raun et al., 1998 (Eur J Endocrinol)(opens in a new tab)

References

  1. [1]Raun et al., 1998 (Eur J Endocrinol) (opens in a new tab)

Written by Twenty Residues editorial. Medical review: pending; a named reviewer is being assigned.

Last updated September 19, 2026.

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Update history
  • 2026-09-19 — Sourced review — every claim checked against primary literature; sequence, regulatory status, safety, and FAQs added.