Ipamorelin

Overview

Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) originally developed by Novo Nordisk and later advanced by Helsinn/Nycomed. It is a selective ghrelin receptor agonist / growth hormone secretagogue (GHRP). Its defining feature versus older GHRPs (GHRP-2, GHRP-6, hexarelin) is that in preclinical and early clinical studies it raised GH without meaningfully increasing ACTH, cortisol, or prolactin. It is not FDA-approved for any indication; a Phase 2 trial for postoperative ileus failed to meet its primary endpoint and clinical development was discontinued. In the wellness/grey market it is sold as a research chemical and used off-label for anti-aging and body-composition goals despite no clinically validated human dose for those uses.

Mechanism of Action

Ipamorelin binds the growth hormone secretagogue receptor 1a (GHSR-1a) on pituitary somatotrophs and in the arcuate nucleus of the hypothalamus, mimicking endogenous ghrelin. GHSR-1a is a Gq-coupled GPCR; activation triggers phospholipase C, IP3, and intracellular calcium release, driving pulsatile GH secretion. Ipamorelin's selectivity appears to come from its distinct binding profile at the GHSR compared with GHRP-2/GHRP-6, producing GH release without substantial ACTH/cortisol or prolactin co-release at therapeutic doses. It is pharmacologically complementary to GHRH analogs (sermorelin, CJC-1295) because the two receptor systems converge on somatotroph GH release through different second messengers, producing additive-to-synergistic GH pulses when co-administered.

Research Summary

The seminal preclinical characterization (Raun et al., 1998, PMID 9849822) established ipamorelin as the first GHRP-receptor agonist with GH-release selectivity comparable to GHRH, without raising ACTH or cortisol even at doses more than 200-fold above the ED50. Pharmacokinetic-pharmacodynamic modeling in healthy male volunteers (Gobburu et al., 1999, PMID 10496658) confirmed a roughly 2-hour half-life and dose-dependent GH response following IV infusion. The most advanced human study is Beck et al. (2014, PMID 25331030), a Phase 2, randomized, double-blind, placebo-controlled trial in 114 patients after bowel resection evaluating IV ipamorelin 0.03 mg/kg twice daily for postoperative ileus; the drug was well tolerated but did not separate from placebo on the primary endpoint (time to tolerance of solid food), and the sponsor (Helsinn/Nycomed) discontinued development. There are no completed registrational trials in adult GH deficiency, frailty, or body-composition indications. Ipamorelin is not FDA-approved for any indication. The 100–300 mcg dose range reflects community/compounding practice and is not clinically validated for anti-aging or body-composition use.

Vendors selling Ipamorelin

Scored vendors carrying Ipamorelin, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Prescribers who offer Ipamorelin

239 prescribers in our directory work with Ipamorelin, each confirmed from their own website. Peptides like Ipamorelin require a prescription from a licensed provider — telehealth options are available.

Reported Side Effects

• Injection-site reactions (erythema, itching, transient welt)
• Transient mild water retention / peripheral edema
• Increased appetite (ghrelin-class effect)
• Headache and flushing shortly after injection
• Paresthesias (tingling or numbness in hands or feet)
• Transient post-dose fatigue or lightheadedness
• Reduced insulin sensitivity / elevated fasting glucose with sustained GH elevation, of particular concern when stacked with long-acting GHRH analogs in predisposed individuals

Research Guides

• Cheapest verified Ipamorelin: live prices, vendors & COA data

Compare Ipamorelin with Others

Research References

• Ipamorelin, the first selective growth hormone secretagogue (Raun K et al., Eur J Endocrinol, 1998) (1998)
• Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers (Gobburu JV et al., Pharm Res, 1999) (1999)
• Prospective, randomized, controlled, proof-of-concept study of the ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients (Beck DE et al., Int J Colorectal Dis, 2014) (2014)

Frequently asked questions

Has Ipamorelin been independently lab-tested?

Disclosed Labs has collected 155 Certificates of Analysis (COA) for Ipamorelin from 17 independent testing labs. 37 vendors have submitted material for testing. Products average 99.7% tested purity across the corpus. Full testing data is available at https://www.disclosedlabs.com/peptides/ipamorelin/testing.

What is the average purity of Ipamorelin on the market?

Based on 155 COAs analyzed by Disclosed Labs, Ipamorelin products average 99.7% (±0.3%) tested purity. Individual vendor results vary; see per-vendor COA data at https://www.disclosedlabs.com/peptides/ipamorelin/coas.

Which labs have tested Ipamorelin?

Independent labs that have tested Ipamorelin include: ILS Labs (Grade A), Ethos Analytics (Grade B). Full lab credibility grades and profiles are at https://www.disclosedlabs.com/labs.

Where can researchers source Ipamorelin?

8 vendors with Disclosed Labs trust grades currently list Ipamorelin, including Glacier Aminos, Ion Peptide, Voltera Sciences. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/ipamorelin.

Which prescribers offer Ipamorelin with a prescription?

239 prescribers in the Disclosed Labs directory work with Ipamorelin, each confirmed from their own website, with telehealth options available. Ipamorelin requires a prescription from a licensed provider. Browse them at https://www.disclosedlabs.com/prescribers?peptide=Ipamorelin.

How does Ipamorelin work?

Ipamorelin binds the growth hormone secretagogue receptor 1a (GHSR-1a) on pituitary somatotrophs and in the arcuate nucleus of the hypothalamus, mimicking endogenous ghrelin. GHSR-1a is a Gq-coupled GPCR; activation triggers phospholipase C, IP3, and intracellular calcium release, driving pulsatile GH secretion. Ipamorelin's selectivity appears to come from its distinct binding profile at the GHSR compared with GHRP-2/GHRP-6, producing GH release without substantial ACTH/cortisol or prolactin co-release at therapeutic doses. It is pharmacologically complementary to GHRH analogs (sermorelin, CJC-1295) because the two receptor systems converge on somatotroph GH release through different second messengers, producing additive-to-synergistic GH pulses when co-administered.

What does the research say about Ipamorelin?