A selective synthetic pentapeptide growth-hormone secretagogue (a GHSR-1a agonist) refined from GHRP-1, used in laboratory research to study growth-hormone-specific signaling. It is sold for in-vitro research use only.

How is ipamorelin different from CJC-1295?

They act at different receptors. Ipamorelin is a secretagogue at the ghrelin / GHSR-1a receptor, while CJC-1295 is a GHRH analog at the GHRH receptor. Researchers often pair the two to examine both arms of growth-hormone regulation, but the individual results are not interchangeable.

Is ipamorelin FDA-approved?

No. Ipamorelin is not an approved drug and has not been evaluated by the FDA. It is supplied strictly for in-vitro laboratory research and is not for human or veterinary use.

Do I need bacteriostatic water for it?

No. Our ipamorelin ships pre-mixed as a ready-to-use solution, so there is no lyophilized powder to reconstitute. Store it refrigerated at 2-8°C on arrival, not frozen.

Ipamorelin: what it is and what the literature examines

7 min read · Updated September 2026 · MY PEPTIDES Research Team

Key facts

Ipamorelin is a synthetic pentapeptide growth-hormone secretagogue (Aib-His-D-2-Nal-D-Phe-Lys-NH2) that was refined out of the earlier peptide GHRP-1. It is counted among the first genuinely selective growth-hormone-releasing peptide (GHRP) receptor agonists, stimulating growth hormone with a specificity on par with the body's own GHRH. In biochemical and cell-based work it behaves as an agonist at the ghrelin / growth-hormone secretagogue receptor (GHSR-1a) carried by pituitary somatotrophs. The trait that defines it in the literature is that selectivity: at the concentrations that drive growth-hormone release in experimental models, it leaves adrenocorticotropic hormone (ACTH) and cortisol secretion largely untouched, which makes it a clean way to separate growth-hormone-specific signaling from wider hypothalamic-pituitary-adrenal activity. It is also examined comparatively against other GHRPs such as GHRP-2, GHRP-6 and Hexarelin, and paired with GHRH analogs like CJC-1295 to probe two arms of growth-hormone regulation at once. For US laboratories it ships pre-mixed as a solution with a batch-specific Certificate of Analysis, cold-chain, with tracked delivery across the United States next business day, priced in US dollars. It is sold only for in-vitro laboratory research: not for human or veterinary use, it carries no therapeutic claims, and it has not been evaluated by the FDA.

Ipamorelin is a synthetic pentapeptide growth-hormone secretagogue, refined from the earlier peptide GHRP-1. Its five-residue sequence (Aib-His-D-2-Nal-D-Phe-Lys-NH2) is short, defined and easy to characterize, and it is regarded as one of the first truly selective growth-hormone-releasing peptide (GHRP) receptor agonists, driving growth-hormone stimulation with a specificity that rivals the body's own GHRH. In the United States it appears in research listings under names like ipamorelin acetate and GHRP (selective), but the compound is the same one described here.

Research use only. Ipamorelin is supplied strictly for in-vitro laboratory research. It is not for human or veterinary use, it has not been evaluated by the FDA, and this page describes no dosing, administration or use in humans or animals, and makes no therapeutic claims.

What ipamorelin is

Ipamorelin belongs to the growth-hormone secretagogue family, compounds that stimulate growth-hormone release by acting at the same receptor as the natural hunger-and-energy hormone ghrelin, rather than at the GHRH receptor. It was developed as a cleaner successor to earlier GHRPs, and the design goal was selectivity: a molecule that switches on growth-hormone signaling without dragging along the off-target hormone responses that its predecessors produced. That is the property the research literature keeps coming back to.

Where the research focuses

In biochemical and cell-based work, ipamorelin acts as an agonist at the ghrelin / growth-hormone secretagogue receptor (GHSR-1a) found on pituitary somatotrophs. Receptor activation couples through Gq/phospholipase C and intracellular calcium signaling to trigger growth-hormone release, and this is the mechanism experiments are built to observe. What the literature returns to is the selectivity: at the concentrations that stimulate growth-hormone release in experimental models, ipamorelin leaves adrenocorticotropic hormone (ACTH) and cortisol secretion largely untouched. That clean separation is what makes it useful, because it lets researchers pull growth-hormone-specific signaling apart from broader hypothalamic-pituitary-adrenal (HPA) activity that confounds less selective secretagogues.

Common applications include:

Mapping GHSR-1a binding, selectivity and downstream signaling
Studying growth-hormone secretagogue activity in isolation from the HPA axis
Comparative work against other GHRPs such as GHRP-2, GHRP-6 and Hexarelin
Combination studies with GHRH analogs, where a secretagogue and a GHRH tool are examined together

As with any receptor agonist, the readouts move with concentration, exposure time and model system, so ipamorelin is used to characterize secretagogue-receptor signaling rather than to predict what happens in a whole organism. It is worth naming the gap between that and the downstream marketing: search results are full of body-composition and recovery language extrapolated from the growth-hormone axis, which is a different thing from the receptor pharmacology the primary literature actually measures.

Paired with GHRH analogs

A GHRH analog and a secretagogue act on two different receptors, so they are frequently studied together to probe both arms of growth-hormone regulation in one system. The most common pairing sets ipamorelin beside CJC-1295, a GHRH analog; the CJC-1295 and Ipamorelin guide covers how that combination is examined, and the CJC-1295 guide covers the GHRH side on its own. Ipamorelin also appears as a component in multi-peptide research blends such as the Hulk Stack.

The reason to keep the two arms distinct is attribution: a GHSR-1a result and a GHRH-receptor result are not interchangeable, and a combined preparation cannot tell you which receptor produced an observed effect. Comparative protocols usually run the singles as well, which is why we also supply the components individually.

Supply and format

We supply ipamorelin as a pre-mixed, ready-to-use solution rather than a lyophilized powder, prepared under controlled conditions and verified by HPLC, with a batch-specific Certificate of Analysis that reports purity by HPLC and confirms identity by mass spectrometry for the exact lot you receive. Every compound is synthesized in our own UK laboratory rather than bought in and relabeled, and each US batch is independently verified in a US laboratory before dispatch. Recent certificates sit in the COA library, and the peptide calculator handles concentration arithmetic if you are working from the vial.

How it ships in the United States

For US laboratories ipamorelin is dispatched cold-chain from the warehouse that serves the United States, with tracked delivery across the country next business day. It is priced in US dollars and payable by Visa, Mastercard or Apple Pay. Because it ships as a solution, there is no powder to reconstitute and no bacteriostatic water to add; store it refrigerated at 2-8°C on arrival, not frozen.

What ipamorelin is not

It is not an approved medicine. It has not been evaluated by the FDA and is not supplied for human or veterinary use.
It is not a GHRH analog. It works through the ghrelin / GHSR-1a receptor, a different target from CJC-1295 and tesamorelin, so their results are not interchangeable.
It is not a non-selective GHRP. Its distinguishing feature is that it does not appreciably drive ACTH and cortisol at growth-hormone-releasing concentrations, which is exactly why it is used as the clean comparator.

Dosing and administration

We do not publish dosing, reconstitution-for-use or administration guidance for ipamorelin. The material is supplied strictly for in-vitro laboratory research and is not for human or veterinary use, so quantity guidance aimed at a person would be inconsistent with what is actually supplied. Experimental concentrations depend on the model and endpoint and belong in the primary literature.

Frequently asked questions

What is Ipamorelin?: A selective synthetic pentapeptide growth-hormone secretagogue (a GHSR-1a agonist) refined from GHRP-1, used in laboratory research to study growth-hormone-specific signaling. It is sold for in-vitro research use only.
Why is ipamorelin described as selective?: Because in experimental models it stimulates growth-hormone release at concentrations that leave adrenocorticotropic hormone (ACTH) and cortisol secretion largely untouched. That clean separation lets researchers isolate growth-hormone-specific signaling from broader hypothalamic-pituitary-adrenal activity, which less selective GHRPs confound.
How is ipamorelin different from CJC-1295?: They act at different receptors. Ipamorelin is a secretagogue at the ghrelin / GHSR-1a receptor, while CJC-1295 is a GHRH analog at the GHRH receptor. Researchers often pair the two to examine both arms of growth-hormone regulation, but the individual results are not interchangeable.
Is ipamorelin FDA-approved?: No. Ipamorelin is not an approved drug and has not been evaluated by the FDA. It is supplied strictly for in-vitro laboratory research and is not for human or veterinary use.
How quickly does ipamorelin ship in the US?: Orders are dispatched cold-chain from the warehouse that serves the United States, with tracked delivery across the country next business day. It is priced in US dollars and payable by Visa, Mastercard or Apple Pay.
Do I need bacteriostatic water for it?: No. Our ipamorelin ships pre-mixed as a ready-to-use solution, so there is no lyophilized powder to reconstitute. Store it refrigerated at 2-8°C on arrival, not frozen.

Continue reading

Sources

PubMed: Ipamorelin / growth-hormone secretagogue literature