GHRP-2, GHRP-6 and Ipamorelin are synthetic peptides that activate the same receptor, the growth hormone secretagogue receptor GHS-R1a, which is also the receptor for ghrelin. They differ in length, in sequence and in how selective they are. GHRP-6 came first, GHRP-2 followed as a close relative, and Ipamorelin is a later pentapeptide designed for selectivity.
At a glance
| GHRP-2 | GHRP-6 | Ipamorelin | |
|---|---|---|---|
| Length | 6 amino acids | 6 amino acids | 5 amino acids |
| Sequence | D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2 | His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 | Aib-His-D-2-Nal-D-Phe-Lys-NH2 |
| Also known as | Pralmorelin, KP-102 | Growth hormone releasing hexapeptide, SKF-110679 | NNC 26-0161 |
| Receptor | GHS-R1a | GHS-R1a | GHS-R1a |
| Selectivity | Less selective, with reported activity at ACTH and prolactin endpoints | Less selective, with reported activity at ACTH and prolactin endpoints | Minimal cross-activity at ACTH and prolactin endpoints |
| NuVion vial size | 10mg | 10mg | 10mg |
Structure
GHRP-6 and GHRP-2 are hexapeptides that share their last four residues, Ala-Trp-D-Phe-Lys-NH2. They differ at the N-terminus, where GHRP-6 has His-D-Trp and GHRP-2 has D-Ala-D-2-Nal. All three peptides contain D-amino acids, which resist peptidases, and all three end in an amidated lysine.
Ipamorelin is one residue shorter. It opens with aminoisobutyric acid, an unnatural amino acid, and keeps the D-2-naphthylalanine and D-phenylalanine found in GHRP-2.
Mechanism at the receptor level
GHS-R1a is a class A G protein-coupled receptor that signals mainly through Gq, phospholipase C and a rise in intracellular calcium. All three peptides are agonists at it. The two hexapeptides are reported to move ACTH and prolactin endpoints as well, while Ipamorelin is studied for leaving those endpoints largely unchanged. That makes the three a useful series for separating receptor activation from selectivity.
Where each is used in research
- GHRP-6: reference agonist in calcium signalling assays at GHS-R1a
- GHRP-2: receptor activation studies in pituitary somatotroph cultures
- Ipamorelin: receptor selectivity panels across pituitary endpoints
- All three: structure-activity comparisons among ghrelin receptor ligands
Supplied by NuVion
NuVion stocks GHRP-2, GHRP-6 and Ipamorelin in Australia as 10mg lyophilised vials. Published certificates are shown on each product page and in the COA library. For the GHRH receptor side of the same axis, see CJC-1295 vs Ipamorelin.
Frequently asked questions
What is the difference between GHRP-2 and GHRP-6?
Two residues at the N-terminus. GHRP-6 begins His-D-Trp and GHRP-2 begins D-Ala-D-2-Nal. The remaining four residues are the same.
How is Ipamorelin different from the GHRPs?
It is a pentapeptide where they are hexapeptides, and it is studied for selectivity, with minimal cross-activity at ACTH and prolactin endpoints.
Are these products therapeutic goods in Australia?
No. NuVion’s GHRP-2, GHRP-6 and Ipamorelin are laboratory chemicals for in vitro research. They are not included in the Australian Register of Therapeutic Goods, have not been assessed by the Therapeutic Goods Administration, and are not for human or veterinary use.
Research use only. These products are laboratory chemicals supplied for in vitro research. They are not included in the Australian Register of Therapeutic Goods and have not been assessed by the Therapeutic Goods Administration for quality, safety or efficacy. They are not for human or veterinary use, and nothing on this page is a representation about therapeutic use.