Peptide

Ipamorelin

Ipamorelin

Evidence TierCWADA PROHIBITED

tuneTypical Dose

4.21-140.45 nmol/kg IV over 15 minutes (published human PK/PD range)

watchEffect Window

Minutes to hours for GH biomarker window. No validated chronic protocol effect.

lockCompliance

WADA PROHIBITED

Overview

Clinical Summary

Ipamorelin is a ghrelin receptor agonist peptide that stimulates growth hormone release. It is used for growth hormone elevation with claims of fewer cortisol and prolactin effects than some related peptides.

Early research suggests growth hormone stimulation with relatively small effects on cortisol and prolactin compared with some other secretagogues. Controlled outcomes evidence for improved body composition, strength, or recovery is limited. The only controlled efficacy trial did not meet its primary endpoint and occurred in a postoperative population, not a wellness setting. Benefits remain uncertain and long-term safety data for nonclinical use are limited.

Ghrelin receptor agonist/secretagogue that drives acute GH release with short, single-pulse pharmacodynamics.

Outcomes

What This Is Expected To Influence

Primary Outcomes

  • Growth hormone pulse response
  • Postoperative GI recovery-time endpoint

Secondary Outcomes

  • Safety and tolerability signal
  • Regulatory/compliance risk

Safety

Contraindications and Interactions

Contraindications

  • Pregnancy
  • Lactation
  • Known pituitary pathology
  • Severe endocrine instability
  • Active malignancy

Side effects

  • Headache
  • Lightheadedness
  • Water retention

Interactions

  • Concurrent GH-axis peptides
  • GH/glucocorticoid-modulating agents
  • Other pituitary-active drugs

Avoid if

  • Competitive athletes
  • Unsupervised use
  • Unknown sourcing/quality
  • Pediatric users

Evidence

Study-level References

ipamorelin-SRC-001Preclinical pharmacology and receptor-profiling study
Sourceopen_in_new

Raun K et al. 1998. "Ipamorelin, the first selective growth hormone secretagogue." Eur J Endocrinol. 1998;139(5): 552-61. DOI: 10.1530/eje.0.1390552; PMID: 9849822. URL: https://pubmed.ncbi.nlm.nih.gov/9849822/

Population: In vitro, swine, and anesthetized rat models

Dose protocol: Mechanistic preclinical GH-releasing dose series

Key findings: Described selective GH secretagogue pharmacology and relatively selective GH release profile compared with some related secretagogues.

Notes: Not a clinical outcome trial.

Paper content

Described selective GH secretagogue pharmacology and relatively selective GH release profile compared with some related secretagogues.

ipamorelin-SRC-002Human PK/PD trial
Sourceopen_in_new

Gobburu JV et al. 1999. "Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers." Pharm Res. 1999;16(9): 1412-6. DOI: 10.1023/A:1018955126402; PMID: 10496658. URL: https://pubmed.ncbi.nlm.nih.gov/10496658/

Population: Healthy male volunteers

Dose protocol: 4.21, 14.02, 42.13, 84.27, and 140.45 nmol/kg IV over 15 minutes

Key findings: Dose-proportional PK with short half-life (~2 h), single GH pulse peak around 0.67 h, and exponential GH decline.

Notes: Acute mechanistic/protocol-only outcome.

Paper content

Dose-proportional PK with short half-life (~2 h), single GH pulse peak around 0.67 h, and exponential GH decline.

ipamorelin-SRC-003Phase II randomized controlled trial
Sourceopen_in_new

Beck DE et al. 2014. "Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients." Int J Colorectal Dis. 2014;29(12): 1527-34. DOI: 10.1007/s00384-014-2030-8; PMID: 25331030. URL: https://pubmed.ncbi.nlm.nih.gov/25331030/

Population: Adults undergoing small and large bowel resection

Dose protocol: 0.03 mg/kg IV twice daily, up to 7 days or discharge

Key findings: No significant primary endpoint difference in time to first tolerated meal (25.3 h vs 32.6 h; p=0.15). AE rates were 87.5% vs 94.8% (ipamorelin/placebo).

Notes: Single clinical efficacy context. Endpoint is postoperative GI recovery.

Paper content

No significant primary endpoint difference in time to first tolerated meal (25.3 h vs 32.6 h; p=0.15); AE rates were 87.5% vs 94.8% (ipamorelin/placebo).

ipamorelin-SRC-004Regulatory classification source
Sourceopen_in_new

World Anti-Doping Agency. "What is prohibited?" WADA official prohibited-list guidance includes S2.2.4 growth hormone-releasing factors, with examples including GH secretagogues such as ipamorelin. URL: https://www.wada-ama.org/en/content/what-is-prohibited

Population: Sports-competitor compliance context

Dose protocol: N/A

Key findings: Class-based restriction context supports anti-doping governance relevance for this compound class.

Notes: Compliance status should be cross-checked annually.

Paper content

Class-based restriction context supports anti-doping governance relevance for this compound class.

ipamorelin-SRC-005Reference definition
Sourceopen_in_new

National Cancer Institute. "Ipamorelin." NCI Drug Dictionary. URL: https://www.cancer.gov/publications/dictionaries/cancer-drug/def/ipamorelin

Population: General

Dose protocol: N/A

Key findings: Defines ipamorelin as ghrelin mimetic with GH-releasing receptor activity.

Notes: Mechanistic descriptor only.

Paper content

Defines ipamorelin as ghrelin mimetic with GH-releasing receptor activity.

ipamorelin-SRC-006Regulatory identifier record
Sourceopen_in_new

U.S. Food and Drug Administration. "UNII - Y9M3S784Z6 | IPAMORELIN." Precision.FDA UNII Search Service. URL: https://precision.fda.gov/uniisearch/srs/unii/y9m3s784z6

Population: General

Dose protocol: N/A

Key findings: Confirms chemical identity and explicitly states UNII availability does not imply regulatory review/approval.

Notes: Identity confirmation only.

Paper content

Confirms chemical identity and explicitly states UNII availability does not imply regulatory review/approval.

ipamorelin-SRC-007Compliance guidance list
Sourceopen_in_new

U.S. Anti-Doping Agency. "Screen Your Dietary Supplements." USADA. URL: https://www.usada.org/dietary-supplements/screen-dietary-supplements/

Population: Athletes and anti-doping users

Dose protocol: N/A

Key findings: Contains "Ipamorelin - Prohibited at all times" in supplement-focused prohibited substance list.

Notes: Historical page note indicates reference context. Users must verify current season/authority policy.

Paper content

Contains "Ipamorelin – Prohibited at all times" in supplement-focused prohibited substance list.

Guides

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