Ipamorelin vs GHRP-2 — How the Two Secretagogues Compare
Ipamorelin and GHRP-2 are both synthetic growth hormone secretagogue research peptides, and they are often compared. They are structurally different — a pentapeptide versus a hexapeptide — and this page sets out the factual differences for researchers.
Last updated: 2026-08-21 · By: Index Peptides technical team
| Ipamorelin | GHRP-2 | |
|---|---|---|
| Structure | Pentapeptide (5 amino acids) | Hexapeptide (6 amino acids) |
| CAS number | 170851-70-4 | 158861-67-7 |
| Molecular weight | ~711.9 g/mol | ~817.0 g/mol |
| Research context | GH secretagogue research | GH secretagogue research |
| Index Peptides formats | 5mg | 10mg |
Different structures
Ipamorelin is a synthetic pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2); GHRP-2 is a synthetic hexapeptide (D-Ala-D-2-Nal-Ala-Trp-D-Phe-Lys-NH2). Both are studied as growth hormone secretagogues, but they are distinct compounds with different CAS numbers and molecular weights.
Chemistry
Ipamorelin is CAS 170851-70-4 at approximately 711.9 g/mol. GHRP-2 is CAS 158861-67-7 at approximately 817.0 g/mol. Both are supplied as lyophilised powders and are commonly handled as acetate salts; the exact form is recorded on each batch's certificate of analysis.
Research literature
Both peptides appear in preclinical literature concerned with growth hormone signalling pathways, typically in in-vitro and animal models. Controlled human data are lacking, and no conclusions about effects in humans can be drawn from this body of work.
Regulatory status
Neither compound is an approved medicine, and both are prohibited in sport by the World Anti-Doping Agency (WADA). Index Peptides supplies both strictly for in-vitro laboratory research — not for human or veterinary use of any kind.
Frequently asked questions
Which is 'better' — ipamorelin or GHRP-2?
Neither is 'better'. They are different peptides from different structures, and Index Peptides takes no position on any application. The documentation — identity, purity and batch record — is what matters when comparing suppliers.
Can they be used together?
Combining research compounds is a matter for the researcher's own protocol. Index Peptides supplies each material separately, strictly for in-vitro laboratory research.
How do I verify the identity of each?
Every released batch of either peptide is HPLC purity tested and LC-MS identity confirmed, with the COA on the product page and batch lookup by lot number.
References
Research use only. Not for human or animal consumption.