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Dr. Grey AI

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
1520

Evidence by condition

  • Strong
  • Moderate
  • Limited
  • Very limited

4 conditions

Metabolic Health

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 effect11 studies

Studies that measured growth hormone release

and 1 more in the citations list

Body Composition

Body Composition: outcomes studied for Ipamorelin
GradeOutcomeEffectSizeStudiesPeopleStudies list
Body Weight

Ipamorelin treatment showed dose-dependent effects on body weight gain in animal models, consistent with growth hormone-mediated anabolic effects.

Changes; see studiesSmall effect11 studies

Studies that measured body weight

and 1 more in the citations list

Muscle Strength

Maximum tetanic muscle tension was significantly increased in animals receiving ipamorelin combined with glucocorticoids, counteracting steroid-induced muscle weakness.

Improves (the measure goes up)Moderate effect5 studies

Studies that measured muscle strength

Bone Health

  • Longitudinal Bone Growth: improves
  • Bone Mineral Content: improves
  • Glucocorticoid-Induced Bone Loss: improves
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 effect8 studies

Studies that measured longitudinal bone growth

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 effect8 studies

Studies that measured bone mineral content

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 effect8 studies

Studies that measured glucocorticoid-induced bone loss

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

Studies that measured gastric motility

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

Studies that measured postoperative recovery

Key findings

  • Growth Hormone ReleaseMetabolic HealthImproves (the measure goes up)
  • Body WeightBody CompositionChanges; see studies
  • Longitudinal Bone GrowthBone HealthImproves (the measure goes up)

Studies cited

22 studies from PubMed

  1. Beyond the androgen receptor: the role of growth hormone secretagogues in the modern management of body composition in hypogonadal malesTransl Androl Urol, 2020 · PMID 32175416
  2. 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
  3. Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileusJ Exp Pharmacol, 2012 · PMID 27186127
  4. Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileusJ Pharmacol Exp Ther, 2009 · PMID 19289567
  5. Growth hormone (GH) hypersecretion and GH receptor resistance in streptozotocin diabetic mice in response to a GH secretagogue.Experimental diabesity research, 2003 · PMID 14630569
  6. Effect of the growth hormone secretagogue, ipamorelin, on markers of bone turnover in female ratsPeptides, 2002 · PMID 12525634
  7. Influence of chronic treatment with the growth hormone secretagogue Ipamorelin, in young female rats: somatotroph response in vitro.Histology and histopathology, 2002 · PMID 12168778
  8. The influence of conformational restriction in the C-terminus of growth hormone secretagogues on their potency.European journal of medicinal chemistry, 2002 · PMID 12204475
  9. The growth hormone secretagogue ipamorelin counteracts glucocorticoid-induced decrease in bone formation of adult ratsGrowth Horm IGF Res, 2001 · PMID 11735244
  10. Growth hormone (GH)-independent stimulation of adiposity by GH secretagogues.Biochemical and biophysical research communications, 2001 · PMID 11162489
  11. Do growth hormone-releasing peptides act as ghrelin secretagogues?Endocrine, 2001 · PMID 11322495
  12. Structural similarity of ghrelin derivatives to peptidyl growth hormone secretagogues.Biochemical and biophysical research communications, 2001 · PMID 11396951
  13. Highly potent growth hormone secretagogues: hybrids of NN703 and ipamorelin.Bioorganic & medicinal chemistry letters, 2001 · PMID 11459660
  14. The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female ratsJ Endocrinol, 2000 · PMID 10828840
  15. Safety and tolerability of ipamorelin, a novel growth hormone-releasing peptideHorm Metab Res, 2000 · PMID 10667906
  16. Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteersPharm Res, 1999 · PMID 10496658
  17. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in ratsGrowth Horm IGF Res, 1999 · PMID 10373343
  18. 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
  19. Ipamorelin, the first selective growth hormone secretagogueEur J Endocrinol, 1998 · PMID 9849822
  20. A new series of highly potent growth hormone-releasing peptides derived from ipamorelinJ Med Chem, 1998 · PMID 9733495
  21. Novel orally active growth hormone secretagogues.Journal of medicinal chemistry, 1998 · PMID 9733496
  22. 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