Ipamorelin is a five amino acid peptide that acts at the ghrelin receptor, the same receptor the hormone ghrelin uses. What makes it worth studying is not that it works, since several older compounds do the same thing, but that it is selective: it activates that receptor with comparatively little effect on cortisol and prolactin, which the earlier generation of secretagogues did not manage.

It is written Ipamorelin, shortened to Ipa, and most often seen as CJC + Ipa when paired with CJC-1295. This guide covers what it is, what selectivity actually means and why it matters, how it compares with GHRP-2, GHRP-6, CJC-1295 and Sermorelin, why pulsatile release changes research design, reconstitution volumes for a 10mg vial, and how to check a batch. Ipamorelin is supplied by PhaseOne in 10mg vials, strictly for laboratory research.

On this page

What is Ipamorelin | What selectivity means | vs GHRP-2 and GHRP-6 | vs CJC-1295 | vs Sermorelin | Pulsatile release | Reconstitution | Checking purity | FAQs

Key points at a glance

• A synthetic pentapeptide, five amino acids, CAS 170851-70-4
• Written Ipamorelin, Ipa, and CJC + Ipa when paired with CJC-1295
• Acts at GHS-R, the ghrelin receptor, as a growth hormone secretagogue
• Selective, meaning comparatively little cortisol or prolactin co-release
• That selectivity is the reason it replaced GHRP-2 and GHRP-6 as the standard comparator
• A different receptor from CJC-1295, which is why the two are paired rather than chosen between
• Growth hormone release is pulsatile, so measurement timing matters more here than in steady-state work
• Supplied in 10mg vials only, at least 99% HPLC purity, certificate published publicly
• For laboratory research only

What is Ipamorelin?

Ipamorelin is a synthetic peptide of just five amino acids, built to activate the growth hormone secretagogue receptor, usually written GHS-R. That is the receptor ghrelin binds, which is why compounds acting on it are called secretagogues: they prompt release rather than supplying a hormone.

It sits in the family generally labelled GHRPs, growth hormone releasing peptides, though that label is slightly misleading. The original GHRPs were not selective, and Ipamorelin was designed specifically to fix that. In pharmacological writing it is more precisely described as a selective GHS-R agonist.

Its short sequence has a practical consequence worth knowing: five amino acids are easier to synthesise consistently than a 29 or 44 amino acid chain, so batch to batch variation tends to be lower than for longer peptides in the same category.

What selectivity actually means

Selectivity is the word that does all the work in any Ipamorelin description, and it is usually left vague. Concretely: the ghrelin receptor sits in a system where activation can also drive cortisol, ACTH and prolactin release. Older secretagogues triggered all of it together.

Ipamorelin activates GHS-R while leaving those other pathways comparatively untouched. For a researcher that is not a marketing point, it is a methodological one. If a compound raises three hormones at once, you cannot attribute an observed effect to any one of them. A cleaner signal means the result is interpretable.

That is also why Ipamorelin became the reference compound in this sub-category: it is the tool you use to work out which effects belong to GHS-R activation itself.

Ipamorelin vs GHRP-2 and GHRP-6

All three act at the same receptor. The difference is what else they do.

PhaseOne does not stock GHRP-2 or GHRP-6. They are listed here because the comparison is the clearest way to explain what Ipamorelin is for, not because we are steering you toward the one we sell. If a protocol specifically needs the broader receptor activity of an older GHRP, Ipamorelin is the wrong compound for it.

Ipamorelin vs CJC-1295

This is the comparison most researchers arrive looking for, and the honest answer is that it is not really a versus. They act on different receptors.

Because the two inputs are independent, they are studied together far more often than they are compared. See the CJC-1295 guide for that compound on its own, or the CJC-1295 and Ipamorelin guide for the pairing in full.

PhaseOne supplies them as separate Ipamorelin and CJC-1295 No DAC vials, or as a single blended vial . Separate vials are the only way to vary one without the other.

Ipamorelin vs Sermorelin

Sermorelin comes up constantly in the same searches, and the two are not the same kind of thing at all. Sermorelin is a GHRH fragment acting at the GHRH receptor, the same side of the system as CJC-1295. Ipamorelin is on the ghrelin receptor side.

PhaseOne does not supply Sermorelin. On the GHRH side of the system the range covers CJC-1295 No DAC , which is the modified version of broadly the same fragment, and Tesamorelin , which is longer and closer to native GHRH. Researchers comparing Sermorelin suppliers in Australia usually end up weighing those two against it.

Where Ipamorelin sits in the GH axis

The growth hormone axis runs in stages, and Ipamorelin sits right at the top, on one of the two receptors that trigger release.

A compound at the top of the axis and a compound at the bottom answer different questions. See the HGH 191AA guide , the IGF-1 LR3 guide and the growth hormone peptide guide .

Why pulsatile release changes the research design

Growth hormone is not released at a steady rate. It comes in bursts, and secretagogues interact with that rhythm rather than flattening it into a sustained elevation.

This has a practical consequence that catches people out. When a measurement is taken relative to dosing can matter more than the amount used, because a sample drawn between pulses and a sample drawn at a peak will read very differently from identical conditions. Protocols that would be fine for a steady-state pathway produce noise here.

It is also the reason the short-acting CJC-1295 No DAC form, rather than the DAC version, is the usual partner: a compound active for days sits across many pulses and makes the timing question harder, not easier.

Reconstituting a 10mg Ipamorelin vial

Ipamorelin arrives as a lyophilised powder and is reconstituted with bacteriostatic water . Research quantities are in micrograms, so the volume added decides whether the draw is measurable at all. Units are on a 100 unit U-100 syringe.

3ml to 5ml is the sensible range. At 1ml a 100mcg draw is a single syringe unit, so a one unit misread doubles or halves the amount, which is not a margin worth accepting. Work out any combination with the peptide dosage calculator , and see the reconstitution guide for technique.

Add the water slowly down the vial wall, swirl rather than shake, then refrigerate once dissolved and keep it out of light. The storage guide covers the stability variables in full.

What the research does not establish

The receptor pharmacology here is better characterised than for most research peptides, because selectivity was the design goal and was therefore measured directly. That is a real strength, and it is also where the overreach starts.

• Selectivity data describes binding behaviour. It does not demonstrate downstream physiological outcomes, and the two get conflated constantly.
• Long-term human outcome data is limited. A well understood mechanism is not the same as a well understood result.
• Most of the detailed mechanistic work is animal-model, and pulsatile release makes cross-study comparison harder than it looks.

Claims about specific human outcomes circulating in research discussion should be traced to a primary source rather than inferred from the receptor selectivity figures.

Checking purity before you order

Short peptides are cheaper and easier to make than long ones, which cuts both ways: synthesis is more consistent, but the margins also make a short peptide an attractive place to cut corners. The check to ask for is HPLC, which separates a sample by retention time so anything else in the vial shows as its own peak.

Every PhaseOne batch is independently tested to a standard of at least 99% purity by HPLC, and the certificate for each batch is published in our public COA library . You can read the result before ordering rather than taking a purity claim on trust. No COA is shipped with the vial; it is simply public.

For how to read a chromatogram, see the HPLC testing guide , and for what any supplier should be able to show you, the research standards guide .

Buying Ipamorelin in Australia

PhaseOne supplies Ipamorelin in 10mg vials from Australian stock, shipped Australia-wide, for laboratory research only, with every batch HPLC tested to at least 99% purity and the certificate published publicly.

One thing specific to this compound is worth checking on any listing. A large share of search results for Ipamorelin are actually blend listings paired with CJC-1295, so confirm whether a page is selling the single peptide or a combination before comparing prices, since a blend vial and a single-peptide vial are not the same product at the same milligram figure.

Researchers studying the pairing order the CJC-1295 and Ipamorelin blend or both vials separately. Browse the full research range .

Related research guides

For the usual pairing, the CJC-1295 and Ipamorelin guide and the CJC-1295 guide . For the other GHRH analogue, the Tesamorelin guide . For the rest of the axis, the HGH 191AA guide and IGF-1 LR3 guide . For the category, the growth hormone peptide guide . For handling, the reconstitution guide and storage guide . For verification, the HPLC testing guide and the COA library .

Frequently Asked Questions

What is Ipamorelin in simple terms?

A synthetic five amino acid peptide that acts at GHS-R, the ghrelin receptor, as a growth hormone secretagogue. Its defining characteristic is selectivity for that receptor, with comparatively little effect on cortisol and prolactin.

What is Ipa peptide?

Ipa is the common shorthand for Ipamorelin. It appears most often as CJC + Ipa, meaning Ipamorelin paired with CJC-1295 No DAC.

What does selective mean for Ipamorelin?

It activates the ghrelin receptor while leaving the cortisol, ACTH and prolactin pathways comparatively untouched. That matters methodologically: if a compound moves three hormones at once, an observed effect cannot be attributed to any one of them.

Is Ipamorelin the same as GHRP-2 or GHRP-6?

No. All three act at the same receptor, but the older GHRPs also drive cortisol, prolactin and appetite signalling. Ipamorelin was designed to avoid that, which is why it became the standard comparator.

Does PhaseOne supply GHRP-2 or GHRP-6?

No. They are discussed here because the comparison explains what Ipamorelin is for. If a protocol specifically needs the broader receptor activity of an older GHRP, Ipamorelin is the wrong compound.

What is the difference between Ipamorelin and CJC-1295?

Different receptors. Ipamorelin acts at the ghrelin receptor, CJC-1295 at the GHRH receptor. They are studied together far more often than they are compared, because the two signals are independent.

What is the difference between Ipamorelin and Sermorelin?

Sermorelin is an unmodified GHRH fragment acting at the GHRH receptor, the same side of the system as CJC-1295. Ipamorelin is on the ghrelin receptor side. PhaseOne does not supply Sermorelin.

How does Ipamorelin differ from HGH?

Ipamorelin prompts the pituitary to release growth hormone. HGH 191AA is growth hormone itself. One acts on the signal, the other supplies the hormone.

Why does pulsatile release matter?

Growth hormone comes in bursts rather than at a steady rate. A sample drawn between pulses and one drawn at a peak will read very differently under identical conditions, so measurement timing relative to dosing can matter more than the amount used.

Why is the short-acting CJC-1295 the usual partner?

Because a compound active for days sits across many growth hormone pulses, which makes the timing question harder. The No DAC form, active for hours, can be timed alongside a short-acting partner.

What vial size does Ipamorelin come in?

10mg of lyophilised powder. 5mg vials are not part of the current range.

How much bacteriostatic water should a 10mg Ipamorelin vial be reconstituted with?

3ml to 5ml is the sensible range, giving 3.3mg/ml or 2mg/ml. At 1ml a 100mcg draw is a single syringe unit, so a one unit misread doubles or halves it. The table above converts each option to units.

How should Ipamorelin be stored?

Lyophilised vials refrigerated and out of light. Once reconstituted, refrigerate immediately, keep it dark, and prepare only what the work needs.

How is Ipamorelin purity verified?

By independent HPLC testing, which separates the sample by retention time so anything else in the vial appears as its own peak.

What purity is PhaseOne Ipamorelin?

At least 99% by independent HPLC testing, with the certificate for each batch published in our public COA library.

Does a COA come with the vial?

No. Certificates are not shipped with orders. Every batch certificate is published in our public COA library instead, so anyone can check a result before buying.

Is Ipamorelin approved in Australia?

No. It is not registered on the ARTG and is not approved for supply as a medicine, so no pharmacy or chemist stocks it. It is supplied through research suppliers for laboratory research only.

Where can I buy Ipamorelin in Australia?

PhaseOne supplies Ipamorelin 10mg vials from Australian stock, shipped Australia-wide, for laboratory research only. Check whether a competing listing is the single peptide or a CJC-1295 blend before comparing prices.

Disclaimer

All products supplied by PhaseOne are intended strictly for laboratory research purposes only. Products are not intended for human consumption, therapeutic use, cosmetic use, veterinary use, or diagnostic applications.