CJC-1295 DAC is a GHRH analog carrying a Drug Affinity Complex (DAC) modification that binds covalently to circulating albumin, greatly extending its plasma half-life relative to unmodified or short-acting GHRH analogs. Through this albumin binding it acts as a long-lasting agonist at pituitary GHRH receptors, associated in research with sustained growth hormone and downstream IGF-1 elevation. This contrasts with the non-DAC form (Mod GRF 1-29), whose action is measured in minutes rather than days.

MK-677 mimics the action of ghrelin by binding to and activating the GHSR-1a receptor in the pituitary gland, stimulating pulsatile GH release. Its oral bioavailability distinguishes it from peptide-based GH secretagogues and its prolonged half-life results in sustained IGF-1 elevation. Research protocols have explored its effects on lean body mass, bone mineral density, and sleep architecture.