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Practical reference · maintained document

Ipamorelin — reference

Maintainers: np_gilmore, titration_diary, blank_injection Last updated 28 April 2025 Next review due 13 March 2027 514 words · 4 revisions
Sourced from a discussion. This document was promoted out of Follow-up: Evidence quality in the secretagogue literature: an honest assessment, in Secretagogues & GH axis. That topic links back here, and corrections raised there flow into this page.

Ipamorelin: selective growth hormone secretagogue (research use only), approximate mass 711.9 Da, 2 h half-life. Identity, evidence base, analytical considerations and limitations.

Scope

A maintained identity and evidence reference for Ipamorelin. It is deliberately narrow: what the molecule is, what has been published about it, and what an analytical report on it can and cannot establish. It contains no dosing recommendations and is not advice about anyone's care.

Where a figure is approximate this page says so. Where something is unknown, it says that instead of filling the gap.

Identity

FieldValue
ClassSelective growth hormone secretagogue (research use only)
Approximate molecular mass≈ 711.9 Da
Molecular formulaC38H49N9O5
Elimination half-life≈ 2 h
Route and scheduleSubcutaneous in research settings
Regulatory statusResearch use only

Masses quoted here are approximate and are given for orientation when reading an analytical report. For a mass-error calculation, use the exact monoisotopic mass computed from the elemental composition rather than a rounded figure from a reference page, including this one.

What it is

Ipamorelin is a pentapeptide secretagogue whose selling point is selectivity: less effect on cortisol and prolactin than earlier GHRPs. The selectivity claim originates in preclinical characterisation and is reasonably well supported for what it claims.

It was investigated clinically for post-operative ileus and was not taken forward. That development history is more informative than most of what is written about it online.

Evidence base

Published studies and programmes most relevant to this compound:

  • Small clinical studies, including in post-operative ileus, not pursued to registration

A short pentapeptide is trivially easy to confirm analytically, which means there is no excuse for an unverified identity on this compound.

Individual digests for several of these are maintained separately in this commons and are linked from the evidence category. A digest is a summary with its criticisms attached; it is not a substitute for reading the paper.

Analytical considerations

Reversed-phase HPLC with ultraviolet detection at 214 nm is the usual purity method, and electrospray mass spectrometry the usual identity method. A purity figure is an area percentage at a stated wavelength under a stated gradient, and it is not interchangeable with a content determination.

Three things a purity assay on this compound will not tell you: how much peptide is in the container (that requires a content assay), what the counter-ion is (that requires ion chromatography or NMR), and whether anything is present that does not elute under the method used.

See Reversed-phase HPLC for peptides and LC-MS identity confirmation for the method detail.

Status and legality

Research use only.

Material sold as research-use-only is not a licensed medicine, whatever it contains and however good its certificate is. That is a statement about regulatory status rather than about quality, and it is true of high-purity material as much as of poor material.

Limitations of this page

This is a reference page maintained by volunteers, reviewed on the date shown, and it will be out of date at some point after that date. It summarises published work rather than reproducing it, and a summary always loses something. Where the summary and the source disagree, the source is right.

If you find an error, the fastest route to fixing it is a topic in doc review naming the sentence and the source. The maintainers named above are notified.

Revision history

2025-04-28excursion_checkAdded cross-references to the two topics that most often ask this question.
2024-12-31TL4_HalvorsenReverted an unsourced change and asked the editor to re-apply it with a citation.
2024-10-03crossref_checkRestructured into shorter sections so the outline navigation is usable.
2024-08-03KLindqvistInitial promotion from the source topic. Structure taken from the marked solution.

Every edit to a maintained document records its author and a note explaining the change. An edit without a note may be reverted by any wiki editor under R9, and the revert is logged. Disagreements about content belong on the source topic rather than in the revision history (R10).

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