What the two compounds are
CJC-1295 is a modified fragment of growth-hormone-releasing hormone, GHRH(1-29), with four amino-acid substitutions that resist enzymatic degradation. It acts at the GHRH receptor. The name is used for two distinct molecules, which is the single biggest source of confusion in this category, and the distinction is covered in the next section.
Ipamorelin is a synthetic pentapeptide ghrelin-receptor (GHS-R1a) agonist, described by Raun et al. (1998) as the first selective growth hormone secretagogue: it stimulated GH release in their models without the prolactin and ACTH elevation seen with earlier secretagogues.[3]
The two therefore engage different receptors on the same axis, which is why they are studied together.

