Ipamorelin vs sermorelin vs tesamorelin

Ipamorelin, sermorelin and tesamorelin act at two different receptors. Ipamorelin is a five-residue agonist at the ghrelin receptor (GHS-R1a), while sermorelin and tesamorelin are analogs of growth-hormone-releasing hormone (GHRH) that act at the GHRH receptor. The comparison is one ghrelin agonist against two GHRH analogs, which is why research protocols tend to pair ipamorelin with one of the other two rather than pick between them. HGH and MK-677 turn up in the same searches, and neither is the same thing as ipamorelin.

Ipamorelin, sermorelin and tesamorelin side by side

Sermorelin and tesamorelin differ in how much of the hormone they keep. Sermorelin is the first 29 residues of GHRH with nothing added, the shortest fragment that keeps full activity. Tesamorelin keeps all 44 residues and caps the N-terminus to slow enzymatic breakdown. Sermorelin vs tesamorelin vs CJC-1295 sets those two against CJC-1295 in detail.

Ipamorelin is a different kind of molecule. Its sequence is Aib-His-D-2Nal-D-Phe-Lys-NH2, and it is known for selectivity: in the study that first characterised it, it did not raise ACTH or cortisol the way GHRP-2 and GHRP-6 did. GHRP-2 vs GHRP-6 vs ipamorelin compares it with the older ghrelin agonists.

Why ipamorelin is paired with a GHRH analog

Growth-hormone release responds to at least two separate signals. GHRH acts at the GHRH receptor and ghrelin acts at GHS-R1a. Sermorelin and tesamorelin mimic the first signal, ipamorelin the second, so a study of growth-hormone signalling can include one from each side and look at both receptors at once.

pepuro sells two of those pairings in a single vial, both 1:1 by mass:

• CJC-1295 no-DAC + ipamorelin, in 10 mg (5 + 5) and 20 mg (10 + 10) vials. CJC-1295 and ipamorelin explains why the no-DAC form is the one used.
• Tesamorelin + ipamorelin, in 5 mg + 5 mg and 10 mg + 10 mg vials. Tesamorelin and ipamorelin covers that blend.

There is no sermorelin and ipamorelin blend in the catalog, so that pairing means two single vials reconstituted separately. Separate vials also let a protocol set its own ratio. What is a peptide blend? goes through what a blended vial does and does not tell you.

A 1:1 ratio by mass is not 1:1 by molecule count. The three peptides span a sevenfold range in mass, so the same label figure holds very different amounts:

Ipamorelin is 4.7 times lighter than sermorelin and 7.2 times lighter than tesamorelin. At the same mg/mL, the molar concentrations are nowhere near each other. The ipamorelin handling guide has its concentration table and storage notes.

Ipamorelin vs HGH

HGH, or somatropin, is growth hormone itself. The version we sell is recombinant: 191 amino acids, formula C990H1528N262O300S7, about 22,124 g/mol, CAS 12629-01-5. Ipamorelin is roughly 31 times lighter.

The two sit at different points in the same pathway. Ipamorelin is a secretagogue, a compound that acts at a receptor signalling for growth-hormone release. HGH is the hormone that gets released. Studying ipamorelin tells you about the signal, and studying HGH tells you about the hormone downstream of it.

They are also labelled differently. Ipamorelin vials are stated by mass, in milligrams. HGH vials are stated in international units (10, 12, 20, 24 and 36 IU), so concentration after reconstitution is worked out in IU per mL rather than mg per mL.

Is ipamorelin the same as MK-677?

No. MK-677, also called ibutamoren, acts at the same ghrelin receptor as ipamorelin, which is why the two get compared. Chemically they are unrelated. Ipamorelin is a peptide, a chain of five amino acids. MK-677 is a non-peptide small molecule.

pepuro does not sell MK-677. The peptide relatives of ipamorelin at the same receptor are GHRP-2, GHRP-6 and hexarelin, all six-residue chains.

Checking the vial

An ipamorelin report should show an observed mass near 711.85 and HPLC purity at 99% or higher, with a batch number that matches the vial and a named lab. A blend has two identities to confirm, so its report should list both peptides with their own mass and purity lines. How to read a peptide lab report walks through each field.

Every ipamorelin vial and blend from pepuro ships free, from our Calgary, Toronto and Vancouver distribution centers, the same business day your e-Transfer clears, with a QR code on the vial that opens its independent, third-party lab report.

For research use only. Not for human or animal consumption.