Ipamorelin
Ipamorelin is a synthetic pentapeptide consisting of 5 amino acids (Aib-His-D-2-Nal-D-Phe-Lys-NH2) classified as a growth hormone secretagogue receptor (GHSR) agonist, specifically targeting the ghrelin receptor. Originally developed by Novo Nordisk in the late 1990s, ipamorelin represents one of the most selective growth hormone-releasing peptides (GHRPs) available, demonstrating minimal activation of secondary hormone pathways compared to other compounds in its class.
This peptide has gained attention in anti-aging and regenerative medicine due to its ability to stimulate endogenous growth hormone (GH) and insulin-like growth factor-1 (IGF-1) release while maintaining a favorable safety profile. Ipamorelin's selectivity for GH release, without significantly affecting cortisol, prolactin, or acetylcholine pathways, distinguishes it from other growth hormone secretagogues.
Overview
Ipamorelin features several unique structural modifications, including the presence of 2-naphthylalanine (2-Nal) and D-amino acids, which contribute to its stability and receptor selectivity. The peptide is metabolized primarily through peptidase enzymes and eliminated through renal excretion, with metabolites detectable for up to 24 hours post-administration.
Chemical structure & Properties
- Molecular Formula: C38H49N9O5
- Molecular Weight: 711.85 Da
- Sequence: Aib-His-D-2-Nal-D-Phe-Lys-NH2
- Half-life: Approximately 2 hours (plasma elimination)
- Stability: Stable in aqueous solution when refrigerated, susceptible to degradation at room temperature
Mechanism of Action
Ipamorelin exerts its therapeutic effects through multiple interconnected molecular pathways:
Areas Investigated in
the Research Literature
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Current Clinical Evidence
Safety Profile and Considerations
Regulatory Status and Legal Considerations
Regulatory information current as of 28 August 2026. This is a summary, not legal or medical advice, and status can change.
FDA Status
- Classification: Investigational new drug (IND) - not approved for therapeutic use
- Approval Status: No FDA approval for human clinical applications
- Research Use: Limited to approved clinical trials and research protocols
- Regulatory Position: Dual status as of April 22, 2026: (1) Nominated but Withdrawn from Category 2 for 503A compounding pharmacies. (2) Still listed on the active Category 2 table for 503B outsourcing facilities — 503B compounding remains prohibited. This status is subject to change; current FDA guidance should be checked before any compounding.
WADA Status
- Classification: Prohibited under S2: Peptide Hormones, Growth Factors
- Athletic Use: Banned in competitive sports
- Testing: Detectable through specialized anti-doping analysis
- Violation Consequences: Subject to sporting sanctions and disqualification
Legal Availability
- Ipamorelin is not FDA-approved. Its compounding status is unsettled: the Category 2 nomination was withdrawn for 503A pharmacies while it remains on the Category 2 table for 503B outsourcing facilities, and an FDA advisory committee voted against adding it to the 503A bulks list in October 2024. Material sold outside licensed pharmacy channels is research-grade and of unverified purity.
Conclusion
What the evidence supports
Ipamorelin is a selective growth-hormone secretagogue studied in animal models and small human studies for effects on growth hormone release and body composition. Human outcome data is limited, dosing has not been standardized, and there is no long-term safety data. Ipamorelin is not FDA approved for any therapeutic use; as of April 2026 it was withdrawn from the Category 2 list for 503A compounding while remaining on the Category 2 table for 503B outsourcing facilities, where compounding stays prohibited. This page summarizes the published research and nothing further.
IPAMORELIN SCIENTIFIC
DATA SUMMARY
About this library
This library is published for education. It summarizes published research on compounds studied in this field. Many have no approved medical use, and several cannot lawfully be compounded in the United States. The presence of a page here does not mean Paragon offers that compound. Nothing on these pages is an offer to treat.
This page is general education about a compound studied in this field. Nothing here is medical advice, a recommendation, or an offer to prescribe or supply. A page appearing in this library does not mean Paragon Sports Medicine offers that compound.
Disclaimer: This information is provided for educational purposes only and does not constitute medical advice. Ipamorelin is not approved by the FDA for human therapeutic use. Patients should consult with qualified healthcare providers before considering any peptide therapy.
Ipamorelin acetate has a dual 503A/503B status. See the FDA Status section above.
Statements on this page have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Many peptides described here are not FDA approved for the uses discussed, and some cannot lawfully be compounded in the United States. Nothing on this page is medical advice or a recommendation for any individual. Whether any therapy is appropriate depends on your history, your laboratory results, and a clinical evaluation. Individual results vary. This page is published for education. Use of this site does not create a physician-patient relationship.