Ipamorelin
First described by Raun and colleagues at Novo Nordisk (1998) as 'the first selective growth hormone secretagogue' because it releases GH without meaningfully raising ACTH, cortisol or prolactin. Human evidence is confined to phase 1/2 studies and there is no approved therapeutic indication.
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Mechanism
In plain terms it acts like the hunger hormone ghrelin to switch on growth-hormone release. Technically it is an agonist at the growth hormone secretagogue receptor GHS-R1a (the ghrelin receptor) on pituitary somatotrophs; receptor activation couples through Gq/11 and phospholipase C to generate IP3, releasing intracellular calcium and driving exocytosis of stored growth hormone. Its relative selectivity for GH over ACTH, cortisol and prolactin distinguishes it from earlier secretagogues (Raun et al., 1998).
Regulatory Status by Region
- United States (FDA)Not approved for any indication. FDA removed ipamorelin acetate from Category 2 of the interim 503A bulks list (September 2024) after the nomination was withdrawn and did not add it to the compoundable 503A list; PCAC review did not support inclusion.
- Australia (TGA)Not on the ARTG; an unapproved growth hormone secretagogue. Supply for human therapeutic use is restricted (prescription-only class) with no approved indication.
- European Union (EMA)No EMA marketing authorization; not an approved medicine in the EU.
- WADAProhibited at all times under Section S2; growth hormone secretagogues including ipamorelin are explicitly listed.
Key Studies
- Ipamorelin, the first selective growth hormone secretagogue (opens in a new tab) (Raun K, Hansen BS, Johansen NL, et al. Eur J Endocrinol. 1998;139(5):552-561. PMID 9849822)
- Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients (opens in a new tab) (Beck DE, et al. Int J Colorectal Dis. 2014;29(12):1527-1534 (phase 2 RCT, n=114; NCT00672074; negative primary endpoint))
Related Clinical Trials
Latest research
- Peptide Supplements and Their Therapeutic Applications in Sports Medicine. (opens in a new tab)
The American journal of sports medicine · Aug 11, 2026
Common Questions
- What is Ipamorelin?
- Ipamorelin is a synthetic pentapeptide that mimics ghrelin, selectively prompting the pituitary to release growth hormone in pulses. It is not an approved drug; its most rigorous human trial, for postoperative ileus, failed its primary endpoint and development was discontinued. It is prohibited in sport by WADA and is not eligible for US pharmacy compounding.
- Is Ipamorelin approved for medical use?
- Ipamorelin is not approved for medical use and is prohibited in one or more regulatory or anti-doping frameworks. United States (FDA): Not approved for any indication. FDA removed ipamorelin acetate from Category 2 of the interim 503A bulks list (September 2024) after the nomination was withdrawn and did not add it to the compoundable 503A list; PCAC review did not support inclusion. European Union (EMA): No EMA marketing authorization; not an approved medicine in the EU. Australia (TGA): Not on the ARTG; an unapproved growth hormone secretagogue. Supply for human therapeutic use is restricted (prescription-only class) with no approved indication.
- How does Ipamorelin work?
- In plain terms it acts like the hunger hormone ghrelin to switch on growth-hormone release. Technically it is an agonist at the growth hormone secretagogue receptor GHS-R1a (the ghrelin receptor) on pituitary somatotrophs; receptor activation couples through Gq/11 and phospholipase C to generate IP3, releasing intracellular calcium and driving exocytosis of stored growth hormone.
- Is Ipamorelin legal in Australia?
- Ipamorelin in Australia (TGA): Not on the ARTG; an unapproved growth hormone secretagogue. Supply for human therapeutic use is restricted (prescription-only class) with no approved indication.
- Is Ipamorelin banned in sport?
- Ipamorelin under the World Anti-Doping Agency (WADA) code: Prohibited at all times under Section S2; growth hormone secretagogues including ipamorelin are explicitly listed.