Emerging

Ipamorelin

Selective Growth Hormone Secretagogue Pentapeptide

Ipamorelin is a synthetic pentapeptide growth hormone secretagogue that acts through the ghrelin/GHS receptor to stimulate pulsatile growth hormone release from the pituitary. It is distinguished from other GH secretagogues by its high selectivity — published research shows it stimulates GH release without significantly affecting cortisol, prolactin, or ACTH levels. This selectivity makes it the cleanest GH secretagogue in the research peptide category.

Aliases: GH secretagogue, GHRP

Research score: 7/10

Mechanism

Ipamorelin is a pentapeptide (Aib-His-D-2Nal-D-Phe-Lys-NH2) growth hormone secretagogue that selectively activates ghrelin/GHS-R1a receptors on anterior pituitary somatotrophs. What makes it unique among GHRPs is its remarkable selectivity: it stimulates GH release with potency comparable to GHRP-6 but does not stimulate ACTH, cortisol, prolactin, or aldosterone secretion, even at doses 200-fold above the ED50 for GH release. This selectivity mirrors GHRH rather than other GHRP-receptor agonists. It also shows moderate resistance to metabolism with ~60-80% recovered intact.

Evidence note

Emerging — Some human clinical data (post-surgical applications), extensive pharmacological characterization. The selectivity profile is well-established in clinical pharmacology studies. Less clinical trial data than sermorelin or tesamorelin for anti-aging applications.

Reality layer

Community evidence

Source window English Reddit Updated 12 Aug 2026 · 6-month window
Coverage confidence Low Confidence in the available community sample
Distribution Pending Not enough data for a distribution.

Selected reports

u/Cool-Investigator983

r/BodyHackGuide · Post

6 months ago

Did it exclusively in the evening before bed and noticed results immediately. Take it on an empty stomach, roughly two hours after eating. 2 u/Cool-Investigator983 avatar Cool-Investigator983 ... I'm currently running this now. I've seen much more restful sleep within the

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u/jorfydorfy

r/Biohackers · Post

6 months ago

Last night I took my first ever dose of Tesa/ipa (starting with 0.5mg Tesa / 0.2mg ipa) and mannn I feel like crap today. I was under the impression that my sleep quality would improve but tbh I slept okay? Got enough sleep but woke up sporadically and felt so groggy in the

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Based on 2 qualifying reports from 2 threads. 35 candidates excluded as duplicates, promotion, deleted content, or lacking concrete personal experience. Reddit self-reports are not medical evidence or proof of causation.

Studies

Ipamorelin, the first selective growth hormone secretagogue
First GHRP with selectivity for GH similar to GHRH; no ACTH/cortisol increase even at 200x the ED50 for GH release.
Open source · PMID 9849822
Pharmacological characterization of ipamorelin
5-fold lower systemic clearance than GHRP-6; 60-80% recovered intact. Clean, dose-dependent GH release without desensitization.
Open source · PMID 9849822
Ipamorelin in post-surgical GI recovery
Improved bowel function post-surgery in human clinical studies. One of the few GH secretagogues with human clinical trial data.

FAQ

What makes ipamorelin different from other GH secretagogues like GHRP-6?

Ipamorelin is the most selective GH secretagogue identified. Unlike GHRP-6 (which causes intense hunger) or GHRP-2 (which elevates cortisol and prolactin), ipamorelin stimulates growth hormone release without significantly affecting cortisol, prolactin, ACTH, or aldosterone — even at doses 200x above the effective dose. This selectivity makes it the cleanest option for GH research.

Can ipamorelin be stacked with sermorelin or CJC-1295?

Yes — ipamorelin (ghrelin receptor pathway) and sermorelin or CJC-1295 (GHRH receptor pathway) work through two completely different receptor systems on the pituitary. Published research suggests dual-pathway stimulation produces greater GH release than either alone. The ipamorelin + CJC-1295 (no DAC) combination is one of the most studied GH peptide stacks in the research community.

When should ipamorelin be administered for best results?

Most research protocols administer ipamorelin before bed on an empty stomach (2-3 hours post-meal) to amplify the natural nocturnal GH pulse. Some protocols include a second dose upon waking, also fasted. GH release is blunted by food intake (particularly carbohydrates and fats), so timing around meals matters for optimal pulsatile response.

For research and educational use only. This content is not medical advice.