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Peptide

Ipamorelin

Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that acts as a selective growth hormone secretagogue. It stimulates growth hormone release from the pituitary gland by binding to the ghrelin/GHSR-1a receptor, with notable selectivity that does not significantly affect ACTH or cortisol levels, distinguishing it from other growth hormone releasing peptides.

Research notice. This page is for education and research. Peptides may not be FDA-approved for human use and may only be legally available for research. Talk to a qualified clinician before considering any peptide.

Best evidence
Grade A
Conditions studied
4
Outcomes
8
Graded outcomes
1320

Evidence by condition

  • Strong
  • Moderate
  • Limited
  • Very limited

4 conditions

Metabolic Health: outcomes studied for Ipamorelin
GradeOutcomeEffectSizeStudiesPeopleStudies list
Growth Hormone Release

Ipamorelin potently stimulates growth hormone release in a dose-dependent manner, with effects comparable to GHRP-6 but without affecting cortisol or ACTH levels.

Improves (the measure goes up)Large effect8 studies
Bone Health: outcomes studied for Ipamorelin
GradeOutcomeEffectSizeStudiesPeopleStudies list
Longitudinal Bone Growth

In animal studies, ipamorelin dose-dependently increased longitudinal bone growth rate from 42 μm/day to 52 μm/day, with pronounced effects on body weight gain.

Improves (the measure goes up)Moderate effect7 studies
Bone Mineral Content

12-week treatment with ipamorelin increased total tibial and vertebral bone mineral content in adult rats, primarily through increased bone dimensions rather than volumetric density.

Improves (the measure goes up)Moderate effect7 studies
Glucocorticoid-Induced Bone Loss

Ipamorelin counteracted glucocorticoid-induced decreases in bone formation, with periosteal bone formation rate increasing four-fold when combined with glucocorticoids.

Improves (the measure goes down)Moderate effect7 studies

Digestive Health

  • Gastric Motility: improves
  • Postoperative Recovery
Digestive Health: outcomes studied for Ipamorelin
GradeOutcomeEffectSizeStudiesPeopleStudies list
Gastric Motility

Ipamorelin demonstrated dose-dependent improvement in gastric emptying in rodent models of postoperative ileus, though human clinical trials showed no significant difference versus placebo.

Improves (the measure goes up)Moderate effect5 studies
Postoperative Recovery

In a randomized controlled trial of bowel resection patients, ipamorelin was well-tolerated but showed no significant differences versus placebo in time to first bowel movement or hospital discharge.

NoneNo effect4 studies

Body Composition

  • Muscle Strength
  • Body Weight
Body Composition: outcomes studied for Ipamorelin
GradeOutcomeEffectSizeStudiesPeopleStudies list
Muscle Strength1 study

Studies that measured muscle strength

Body Weight1 study

Studies that measured body weight

Key findings

  • Growth Hormone ReleaseMetabolic HealthImproves (the measure goes up)
  • Longitudinal Bone GrowthBone HealthImproves (the measure goes up)
  • Bone Mineral ContentBone HealthImproves (the measure goes up)

Studies cited

19 studies from PubMed

  1. Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patientsInt J Colorectal Dis, 2014 · PMID 25331030
  2. Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileusJ Exp Pharmacol, 2012 · PMID 27186127
  3. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileusJ Pharmacol Exp Ther, 2009 · PMID 19289567
  4. Growth hormone (GH) hypersecretion and GH receptor resistance in streptozotocin diabetic mice in response to a GH secretagogue.Experimental diabesity research, 2003 · PMID 14630569
  5. Influence of chronic treatment with the growth hormone secretagogue Ipamorelin, in young female rats: somatotroph response in vitro.Histology and histopathology, 2002 · PMID 12168778
  6. The influence of conformational restriction in the C-terminus of growth hormone secretagogues on their potency.European journal of medicinal chemistry, 2002 · PMID 12204475
  7. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult ratsGrowth Horm IGF Res, 2001 · PMID 11735244
  8. Growth hormone (GH)-independent stimulation of adiposity by GH secretagogues.Biochemical and biophysical research communications, 2001 · PMID 11162489
  9. Do growth hormone-releasing peptides act as ghrelin secretagogues?Endocrine, 2001 · PMID 11322495
  10. Structural similarity of ghrelin derivatives to peptidyl growth hormone secretagogues.Biochemical and biophysical research communications, 2001 · PMID 11396951
  11. Highly potent growth hormone secretagogues: hybrids of NN703 and ipamorelin.Bioorganic & medicinal chemistry letters, 2001 · PMID 11459660
  12. The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female ratsJ Endocrinol, 2000 · PMID 10828840
  13. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteersPharm Res, 1999 · PMID 10496658
  14. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in ratsGrowth Horm IGF Res, 1999 · PMID 10373343
  15. Methylprednisolone does not inhibit the release of growth hormone after intravenous injection of a novel growth hormone secretagogue in rats.Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society, 1999 · PMID 10629165
  16. Ipamorelin, the first selective growth hormone secretagogueEur J Endocrinol, 1998 · PMID 9849822
  17. A new series of highly potent growth hormone-releasing peptides derived from ipamorelinJ Med Chem, 1998 · PMID 9733495
  18. Novel orally active growth hormone secretagogues.Journal of medicinal chemistry, 1998 · PMID 9733496
  19. Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption.Xenobiotica; the fate of foreign compounds in biological systems, 1998 · PMID 9879640