Compound Notes · Jul 28, 2026
Ipamorelin vs CJC-1295: Two Different Molecule Classes
These two get compared constantly, usually as though they were interchangeable options in the same category. They are not the same category.
They act on different receptor families
Ipamorelin is a growth hormone secretagogue receptor (GHS-R) ligand. It belongs to the GHRP family, alongside GHRP-2 and GHRP-6.
CJC-1295 is an analogue of growth hormone releasing hormone, so it acts at the GHRH receptor. Different receptor, different family.
That distinction is the whole reason the two are studied together in the literature rather than as alternatives to one another. They are not two versions of one thing.
The size difference is enormous
| Ipamorelin | CJC-1295 (no DAC) | |
|---|---|---|
| Molecular formula | C38H49N9O5 | C152H252N44O42 |
| Molar mass | 711.86 g/mol | 3,367.95 g/mol |
| CAS | 170851-70-4 | 863288-34-0 |
CJC-1295 is roughly 4.7 times the mass of ipamorelin. That is not a detail, it is the single most practical difference between them.
Ipamorelin is a pentapeptide. Five residues assembled by solid-phase synthesis is a short, high-yielding job, and purity above 99% is routine. CJC-1295 is a 29-residue GHRH analogue with a chemical modification, which is many more coupling steps, each one an opportunity for a deletion sequence. The purity spread between suppliers is correspondingly wider.
This is why the two are priced so differently, and why a 99% figure on a pentapeptide is a much weaker signal of supplier quality than the same figure on a 29-residue chain. See why purity figures differ between suppliers.
Handling
Both arrive lyophilized and both dissolve readily in bacteriostatic or sterile water, following the pattern in the reconstitution guide. Neither is unusual to work with.
The larger molecule is the more fragile one in solution. Longer chains have more structure to lose, so CJC-1295 is the less forgiving of the two about freeze-thaw cycles and agitation. Swirl, do not shake, and keep working stock refrigerated rather than repeatedly frozen.
Testing status here
Neither compound currently has an analysed lot in our catalogue. No purity figure exists for either, and we will not quote one borrowed from a different lot or supplier. Current status for every lot is on the lab results page.
Related
Both compounds are supplied as laboratory reagents for research use only. Neither is approved by Health Canada for human or veterinary use.
The compound covered here
- IpamorelinOut of stock
Supplied as a laboratory reagent for research use only. Not for human or veterinary use.
Related reading
- Ipamorelin vs Tesamorelin: Different Receptors, Seven Times the Size
A 712 g/mol pentapeptide acting at one receptor family against a 5,136 g/mol GHRH analogue acting at another. Almost nothing about these two is comparable except that people compare them.
- Peptide Comparisons: The Full Index
Every side-by-side in one place, grouped by what the compounds actually have in common: receptor family, molecule class, or nothing but a reputation for being similar.
- TB-500 vs GHK-Cu: The Largest and Smallest in the Catalogue
A 4,963 g/mol peptide against a 402 g/mol copper complex. A twelvefold size difference changes everything about how the two are made, priced and handled.
- PT-141 vs Melanotan II: One Gram per Mole Apart
Two melanocortin peptides separated by 1 g/mol in molecular weight and by a single structural change. A case where near-identical mass makes mass spectrometry alone a weak identity check.